Abstract 1001: Urinary metabolite diagnostic and prognostic liquid biopsy biomarkers of lung cancer - never smokers versus tobacco smokers

Introduction: Never smokers account for 10-13% of all lung cancer cases in the United States. The etiology is attributed to multiple causes including exposure to passive smoking, parental smoking, asbestos and radon. However, these lung cancer cases do not fit the current United States Government-funded criterion of low-dose computed tomography that identifies early stages of lung cancer with higher survival following surgical removal.

Methods: The cancer urinary biomarkers, creatine riboside (CR) and N-acetylneuraminic acid (NANA), were analyzed and quantified by liquid chromatography-mass spectrometry to determine if never smokers with non-small cell lung cancer (NSCLC) can also be identified alongside tobacco smoker NSCLC cases as compared with gender and age-matched non-cancer population controls.

Results: These cancer biomarkers were significantly higher and comparable in never-smokers and tobacco smokers cases compared to population controls. Receiver Operating Characteristics (ROC) analysis in never smokers was equivalent for CR and NANA levels area under the curve (AUC) 0.91. In contrast, combined CR and NANA levels resulted in better predictive performance (AUC 0.94). Kaplan-Meier survival curves showed that high levels of CR and NANA were associated (p<0.05) with increased cancer-specific death in never-smokers and tobacco smokers. Therefore these metabolites are independent of Tobacco smoking. NANA metabolite category factor, histology and stage were independent predictors of survival (p<0.05) in multivariate analyses for never smokers as shown in Table 1.

Conclusions: These results indicate that measuring CR and NANA in liquid biopsy urine could identify never-smoking lung cancer candidates for LDCT screening and warrant prospective studies of these biomarkers in high-risk environments.

Table 1. Univariate and multivariate regression analysis for factors associated with survival in the never smokers population Univariate Analysis Multivariate analysis Factors Levels N HR 95%CI P-value HR 95%CI P-value Stage Early Stage (I & II); Late Stage (III & IV) 145 3.52 2.3, 5.3 <0.001 3.94 2.2, 6.8 <0.001 Histology Adenocarcinoma; Squamous cell carcinoma 114 1.62 0.7, 3.5 0.26 3.42 1.4, 7.9 0.01 CR Category Low; High 166 1.34 0.8-2.1 0.19 1.67 0.9, 3.0 0.08 NANA Category Low; High 166 2.11 1.1-3.9 0.009 2.31 1.0, 5.0 0.02 Age N=166 166 1.00 0.9, 1.0 0.50 0.99 0.9, 1.0 0.4 Sex Male; Female 166 0.87 0.5, 1.2 0.49 0.90 0.5, 1.5 0.7 Race African American; European American 166 0.82 0.2, 2.5 0.75 0.40 0.1, 1.3 0.2

Citation Format: Bhavik Dalal, Takeshi Tada, Daxesh P. Patel, Mohammed Khan, Takahiro Oike, Yasuyuki Kanke, Amelia Parker, Majda Haznadar, Leila Toulabi, Kristopher Krausz, Ana Robles, Elise Bowman, Frank Gonzalez, Curtis Harris. Urinary metabolite diagnostic and prognostic liquid biopsy biomarkers of lung cancer - never smokers versus tobacco smokers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1001.

Extracellular matrix profiles determine risk and prognosis of the squamous cell carcinoma subtype of non-small cell lung carcinoma

BACKGROUND

Squamous cell carcinoma (SqCC) is a subtype of non-small cell lung cancer for which patient prognosis remains poor. The extracellular matrix (ECM) is critical in regulating cell behavior; however, its importance in tumor aggressiveness remains to be comprehensively characterized.

METHODS

Multi-omics data of SqCC human tumor specimens was combined to characterize ECM features associated with initiation and recurrence. Penalized logistic regression was used to define a matrix risk signature for SqCC tumors and its performance across a panel of tumor types and in SqCC premalignant lesions was evaluated. Consensus clustering was used to define prognostic matreotypes for SqCC tumors. Matreotype-specific tumor biology was defined by integration of bulk RNAseq with scRNAseq data, cell type deconvolution, analysis of ligand-receptor interactions and enriched biological pathways, and through cross comparison of matreotype expression profiles with aging and idiopathic pulmonary fibrosis lung profiles.

RESULTS

This analysis revealed subtype-specific ECM signatures associated with tumor initiation that were predictive of premalignant progression. We identified an ECM-enriched tumor subtype associated with the poorest prognosis. In silico analysis indicates that matrix remodeling programs differentially activate intracellular signaling in tumor and stromal cells to reinforce matrix remodeling associated with resistance and progression. The matrix subtype with the poorest prognosis resembles ECM remodeling in idiopathic pulmonary fibrosis and may represent a field of cancerization associated with elevated cancer risk.

CONCLUSIONS

Collectively, this analysis defines matrix-driven features of poor prognosis to inform precision medicine prevention and treatment strategies towards improving SqCC patient outcome.

Creatine riboside is a cancer cell-derived metabolite associated with arginine auxotrophy

The metabolic dependencies of cancer cells have substantial potential to be exploited to improve the diagnosis and treatment of cancer. Creatine riboside (CR) is identified as a urinary metabolite associated with risk and prognosis in lung and liver cancer. However, the source of high CR levels in patients with cancer as well as their implications for the treatment of these aggressive cancers remain unclear. By integrating multiomics data on lung and liver cancer, we have shown that CR is a cancer cell–derived metabolite. Global metabolomics and gene expression analysis of human tumors and matched liquid biopsies, together with functional studies, revealed that dysregulation of the mitochondrial urea cycle and a nucleotide imbalance were associated with high CR levels and indicators of a poor prognosis. This metabolic phenotype was associated with reduced immune infiltration and supported rapid cancer cell proliferation that drove aggressive tumor growth. CR^hi cancer cells were auxotrophic for arginine, revealing a metabolic vulnerability that may be exploited therapeutically. This highlights the potential of CR not only as a poor-prognosis biomarker but also as a companion biomarker to inform the administration of arginine-targeted therapies in precision medicine strategies to improve survival for patients with cancer.

Higher prevalence of homologous recombination deficiency in tumors from African Americans versus European Americans

To improve our understanding of longstanding disparities in incidence and mortality in lung cancer across ancestry, we performed a systematic comparative analysis of molecular features in tumors from African Americans (AAs) and European Americans (EAs). We find that lung squamous cell carcinoma tumors from AAs exhibit higher genomic instability-the proportion of non-diploid genome-aggressive molecular features such as chromothripsis and higher homologous recombination deficiency (HRD). In The Cancer Genome Atlas, we demonstrate that high genomic instability, HRD and chromothripsis among tumors from AAs is found across many cancer types. The prevalence of germline HRD (that is, the total number of pathogenic variants in homologous recombination genes) is higher in tumors from AAs, suggesting that the somatic differences observed have genetic ancestry origins. We also identify AA-specific copy-number-based arm-, focal- and gene-level recurrent features in lung cancer, including higher frequencies of PTEN deletion and KRAS amplification. These results highlight the importance of including under-represented populations in genomics research.

Insulin resistance and intestinal integrity in children with and without HIV infection in Uganda

OBJECTIVES

The risk of cardiometabolic complications in children with perinatally acquired HIV infection (PHIVs) and in perinatally HIV-exposed but uninfected children (HEUs) and its relationship to systemic inflammation and markers of gut integrity are not well established. In this current study, we assed insulin resitance in PHIV compared to HEUs and HIV unexposed uninfected children and explored potential association with intestinal damage biomarkers.

METHODS

This was a cross-sectional study in PHIVs, HEUs and HIV-unexposed, uninfected children (HUUs) aged 2-10 years enrolled in Uganda. PHIVs were on stable antiretroviral therapy (ART) with HIV viral load  < 400 HIV-1 RNA copies/mL. Insulin resistance was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). We measured markers of systemic inflammation, monocyte activation and gut integrity. Kruskal-Wallis tests were used to compare markers by HIV status; Pearson correlation and multiple linear regressions were used to assess associations of the HOMA-IR index with biomarkers of intestinal damage and translocation.

RESULTS

Overall, 172 participants were enrolled in the study (57 PHIVs, 59 HEUs and 56 HUUs). The median age was 7.8 [interquartile range (IQR) 6.39, 8.84] years, 55% were female and the median body mass index (BMI) was 15 (IQR 14.3, 15.8) kg/m² . Among PHIVs, the median CD4% was 37%, and 93% had viral load ≤ 20 copies/mL. PHIVs had higher waist:hip ratio, high-density lipoprotein (HDL) cholesterol, triglycerides and HOMA-IR index than the other groups (P ≤ 0.02). Factors correlated with insulin resistance included higher BMI and HDL cholesterol and lower soluble tumour necrosis factor receptor I (sTNFRI) (P ≤ 0.02). There was no correlation between any of the other inflammatory or gut biomarkers and HOMA-IR index (P ≥ 0.05). After adjusting for age and sTNFRI, BMI remained independently associated with the HOMA-IR index (β = 0.16; P < 0.01).

CONCLUSIONS

Despite viral suppression, Ugandan PHIVs have disturbances in glucose metabolism. Higher BMI, and not immune activation or alteration of gut integrity, was associated with insulin resistance in this population.

Lung Cancer Risk in Never-Smokers of European Descent is Associated With Genetic Variation in the 5p15.33 TERT-CLPTM1Ll Region

INTRODUCTION

Inherited susceptibility to lung cancer risk in never-smokers is poorly understood. The major reason for this gap in knowledge is that this disease is relatively uncommon (except in Asians), making it difficult to assemble an adequate study sample. In this study we conducted a genome-wide association study on the largest, to date, set of European-descent never-smokers with lung cancer.

METHODS

We conducted a two-phase (discovery and replication) genome-wide association study in never-smokers of European descent. We further augmented the sample by performing a meta-analysis with never-smokers from the recent OncoArray study, which resulted in a total of 3636 cases and 6295 controls. We also compare our findings with those in smokers with lung cancer.

RESULTS

We detected three genome-wide statistically significant single nucleotide polymorphisms rs31490 (odds ratio [OR]: 0.769, 95% confidence interval [CI]: 0.722-0.820; p value 5.31 × 10-16), rs380286 (OR: 0.770, 95% CI: 0.723-0.820; p value 4.32 × 10-16), and rs4975616 (OR: 0.778, 95% CI: 0.730-0.829; p value 1.04 × 10-14). All three mapped to Chromosome 5 CLPTM1L-TERT region, previously shown to be associated with lung cancer risk in smokers and in never-smoker Asian women, and risk of other cancers including breast, ovarian, colorectal, and prostate.

CONCLUSIONS

We found that genetic susceptibility to lung cancer in never-smokers is associated to genetic variants with pan-cancer risk effects. The comparison with smokers shows that top variants previously shown to be associated with lung cancer risk only confer risk in the presence of tobacco exposure, underscoring the importance of gene-environment interactions in the etiology of this disease.

Circulating Inflammation Proteins Associated With Lung Cancer in African Americans

INTRODUCTION

Lung cancer incidence is higher among African Americans (AAs) compared with European Americans (EAs) in the United States. We and others have previously shown a relationship between immune and inflammation proteins with lung cancer in EAs. Our aim was to investigate the etiologic relationship between inflammation and lung cancer in AAs.

METHODS

We adopted a two-stage, independent study design (discovery cases, n = 316; control cases, n = 509) (validation cases, n = 399; control cases, n = 400 controls) and measured 30 inflammation proteins in blood using Meso Scale Discovery V- PLEX multiplex assays.

RESULTS

We identified and validated 10 proteins associated with lung cancer in AAS, some that were common between EAs and AAs (C-reactive proteins [OR: 2.90; 95% confidence interval (CI): 1.99-4.22], interferon γ [OR: 1.55; 95% CI: 1.10-2.19], interleukin 6 [OR: 6.28; 95% CI: 4.10-9.63], interleukin 8 [OR: 2.76; 95% CI: 1.92-3.98]) and some that are only observed among AAs (interleukin 10 [OR: 1.69; 95% CI: 1.20-2.38], interleukin 15 [OR: 2.83; 95% CI: 1.96-4.07], interferon gamma-induced protein 10 [OR: 1.54; 95% CI: 1.09-2.18], monocyte chemotactic protein-4 [OR: 0.54; 95% CI: 0.38-0.76], macrophage inflammatory protein-1 alpha [OR: 1.57; 95% CI: 1.12-2.21], and tumor necrosis factor β [OR: 0.52; 95% CI: 0.37-0.74]). We did not find evidence that either menthol cigarette smoking or global genetic ancestry drove these population differences.

CONCLUSIONS

Our results highlight a distinct inflammation profile associated with lung cancer in AAs compared with EAs. These data provide new insight into the etiology of lung cancer in AAs. Further work is needed to understand what drives this relationship with lung cancer and whether these proteins have utility in the setting of early diagnosis.

Abstract 4925: Microbiome-TP53 gene interaction in human lung cancer

Lung cancer is the leading cancer diagnosis worldwide and the number one cause of cancer deaths. Exposure to cigarette smoke, the primary risk factor in lung cancer, reduces epithelial barrier function and increases susceptibility to infections. Herein, we hypothesized that somatic mutations together with cigarette smoke create a dysbiotic microbiota that is associated with lung carcinogenesis. Using lung tissue from controls (n=33) or cancer cases (n=143), we conducted 16S rRNA gene sequencing (MiSeq), with RNA-seq data from lung cancer cases in The Cancer Genome Atlas (n=1112) serving as the validation cohort. We demonstrate a lower alpha diversity in normal lung as compared to non-tumor adjacent or tumor tissue, indicating a shift in the overall microbial community in lung cancer patients as compared to those without cancer. Lung cancer cases were classified by the relative abundance of two taxa, Variovorax and Streptococcus, with an increase in Variovorax abundance in tumors as compared to non-tumor adjacent paired lung tissue (FDR corrected P=0.013). The species of Variovorax was identified histologically, and also by two additional 16S rRNA strategies (Resphera Insight analysis and PacBio sequencing). A group of taxa were associated with squamous cell carcinoma (SCC), of which Acidovorax were enriched in smokers (P =0.0013). Further, these taxa, including Acidovorax, exhibited higher abundance among the subset of SCC cases with TP53 mutations, an association not seen in adenocarcinomas (AD). Therefore, we observed a microbiome-gene and a microbiome-exposure interaction in SCC lung cancer tissue. Together, these results open the door for future biomarker research that could be used to improve screening and direct mechanistic studies of lung cancer therapy.

Citation Format: Leigh Greathouse, James White, Valery Bliskovsky, Ashley Vargas, Eric Polley, Elise Bowman, Mohammed Khan, Ana Robles, Brid Ryan, Amiran Dzutsev, Giorgio Trinchieri, Marbin Pineda, Sven Bilke, Paul Meltzer, Marina Walther-Antonio, Garth Ehrlich, Joshua Mell, Joshua Earl, Sergey Balashov, Archana Bhat, Alex Valm, Clayton Deming, Sean Conlan, Julia Oh, Julie Segre, Curtis Harris. Microbiome-TP53 gene interaction in human lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4925. doi:10.1158/1538-7445.AM2017-4925

Abstract 1776: Aspirin use among African American men reduces prostate cancer risk: Findings from the NCI-Maryland Prostate Cancer Case-Control study

Prostate cancer is a leading cause of cancer death in US men. Yet, the etiology of prostate cancer remains poorly understood, with only older age, African ancestry, family history of the disease, and multiple germline genetic variations being established disease risk factors. Prostate cancer occurs more often in African-American men and Caribbean men of African descent than in men of other race/ethnicities. The causes of these racial and ethnic differences are multifactorial, but it has been proposed that differences in tumor biology contribute to the health disparity associated with prostate cancer.

Previously, our laboratory discovered immunobiology differences between African-American and European-American men where genes involved in the inflammatory response tended to be up-regulated in tumors of African American patients. Accumulating evidence suggests that inflammation may be involved in prostate carcinogenesis. Given these observations, we hypothesized that inflammation may contribute to prostate cancer risk and the survival health disparity observed between African-Americans and European-Americans. To this end, we conducted a case-control study in the greater Baltimore area where we recruited 1000 cases and 1000 controls composed of equal populations of African-American and European-American men. In our survey, we asked about non-steroidal anti-inflammatory drugs (NSAIDs) use categorized into aspirin, Tylenol, and other pain relievers that neither contain Tylenol nor aspirin. We found a significant association between aspirin use and prostate cancer risk—where aspirin use decreased the risk of prostate cancer. Strikingly, the decreased prostate cancer risk as a result of aspirin use was most profound in African-American men. We were also able to measure the levels of C-reactive protein, a marker for inflammation, to further evaluate the relationship between aspirin use, inflammation, and prostate cancer risk. Indeed, we did observe a decrease in C-reactive protein in patients who took aspirin. Interestingly, overall levels in healthy controls and prostate cases were higher in African-American subjects and patients when compared to European-Americans. Although aspirin use decreased C-reactive protein levels in African-American and European-American cases, African-Americans had significantly higher levels of C-reactive protein. The robust association between aspirin consumption and prostate cancer risk suggests that inflammation might be a driver in prostate cancer of African-American men. Additionally, the increased levels of C-reactive protein in African-American controls and cases might contribute to the excessive disease risk and mortality among these men.

Citation Format: Cheryl J. Smith, Symone Jordan, Tiffany H. Dorsey, Dean Mann, Chris A. Loffredo, Elise Bowman, Wei Tang, Stefan Ambs. Aspirin use among African American men reduces prostate cancer risk: Findings from the NCI-Maryland Prostate Cancer Case-Control study. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1776.

Abstract LB-182: Improved survival among lung cancer patients taking antidepressants

In recent years, the anti-cancer properties of several commonly used drugs have been explored, with drugs such as aspirin and beta-blockers associated with improved cancer outcomes. Emerging evidence suggests that the antidepressant family of drugs may target key pathways in cancer cells, raising the possibility that such drugs could be re-purposed for cancer treatment. Here, using the NCI-MD lung cancer study, we assessed antidepressant use in 1,098 lung cancer patients. Strikingly, antidepressant use was associated with a significant extension of lung cancer-specific survival (HR = 0.78, 95% C.I. = 0.63 - 0.97, P = 0.027) (model adjusted for age, gender, race, smoking status, pack-years of smoking, tumor stage and histology). When assessing distinct classes of antidepressants, we observed that NDRIs (norepinephrine and dopamine reuptake inhibitors) and TCAs (tricyclic antidepressants) were specifically associated with extended survival: TCA HR = 0.40, 95% C.I. = 0.18 - 0.91, P = 0.028 and NDRI HR = 0.61, 95% C.I. = 0.39 - 0.95, P = 0.027). In contrast, SRIs (serotonin reuptake inhibitors) were linked with worse survival (HR 1.94 95% C.I. 1.10 - 2.42, P = 0.023). Importantly, the extended survival time associated with antidepressants was not associated with the typical indications for these drugs, suggestive of a direct effect on lung cancer cells. In addition, as we assessed lung cancer-specific survival we conducted a competing risks analysis, the results of which showed that both NDRIs and TCAs were associated with lung cancer survival (fully adjusted model NDRI, HR: 0.63, 95% C.I. 0.40 - 1.00, P = 0.05) (fully adjusted model TCA, HR: 0.36, 95% C.I. 0.17 - 0.76, P = 0.007). We provide strong evidence that lung cancer patients taking antidepressants, particularly NDRIs and TCAs, have a significantly prolonged survival. Considering the manageable and largely tolerable side effects of antidepressants, and the low cost of these drugs, these results indicate that repositioning antidepressants as adjunct therapeutics with chemotherapy may have a rapid and significant translational impact for lung cancer patients.

Citation Format: Adriana Zingone, Derek Brown, Elise Bowman, Oscar Vidal, Joel Neal, Julien Sage, Brid M. Ryan. Improved survival among lung cancer patients taking antidepressants. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-182. doi:10.1158/1538-7445.AM2015-LB-182

Abstract 4581: Interaction between DRD1 and childhood exposure to environmental tobacco smoke modulates lung cancer risk in smokers and never smokers

In searching for a role for genetic variation in susceptibility to lung cancer, we postulated that miRNA modulating SNPs within smoking behavior associated genes, such as the nicotinic acetylcholine and dopamine receptor families, could modulate susceptibility to tobacco carcinogens and lung cancer risk. Bioinformatic analyses of these gene families identified 5 SNPs predicted to modulate a miRNA binding site. We assessed these SNPs in the National Cancer Institute-MD case-control study (European American [EA] & African Americans [AA] n=1,438). rs686 in DRD1 (dopamine receptor D1) was associated with a reduced risk of lung cancer after adjustment for age, gender and race (OR 0.63, 95% C.I. 0.47-0.85; P=0.002). As DRD1 mediates dopamine signaling following nicotine exposure, we reasoned that the rs686 variant associates with lung cancer risk via modulation of the nicotine reward pathway. However, adjustment for smoking both in terms of smoking status and pack-years did not significantly modulate the association (OR 0.57, 95% C.I. 0.40-0.81, P=0002). In addition, age at smoking initiation, pack-years of smoking and levels of urinary nicotine metabolites (cotinine and hydroxycotinine) did not vary across rs686 genotypes. Moreover, in an analysis of a never smoking cohort from Mayo Clinic, rs686 was also associated with a reduced risk of lung cancer (OR 0.77, 95% C.I. 0.62-0.97; P=0.027; n=629) (pooled analysis OR 0.61, 95% C.I. 0.47-0.78; P&lt;0.0001; n=2,067). Intriguingly, the association between rs686 and lung cancer risk was only observed in subjects exposed to tobacco smoke during childhood (EA smokers: [OR 0.63, 95% C.I. 0.45-0.88; P=0.007] EA never smokers [OR 0.64, 95% C.I. 0.49-0.85; P=0.002] AA smokers OR 0.31, 95% C.I. 0.11-0.89; P=0.029) (model adjusted as above and for education, adult-second-hand smoke exposure). To further explore a relationship between tobacco and DRD1, we exposed lung cancer cell lines to increasing doses of nicotine and observed a significant increase in DRD1 expression (P=0.009). As DRD1 lies within a CpG island, we are currently testing if this regulation occurs via epigenetic modulation of the DRD1 promoter. While a direct role for DRD1 in lung cancer has not previously been reported, a recent report linked DRD to the cancer stem cell hypothesis. Indeed, our work demonstrates that DRD1 is significantly upregulated in lung cells with cancer stem-like properties. Furthermore, miR-296, predicted to bind to variant rs686 allele, is increased in paired lung cancer tissues (P=0.0003), thus linking a decrease in DRD1 with reduced lung cancer risk. Collectively, our work suggests a novel lung cancer pathway whereby rs686 in DRD1 counteracts the increase in DRD1 imposed by exposure to tobacco smoke in both current and never smokers. Furthermore, it hints at a novel role for the dopamine receptor/signaling pathway in lung carcinogenesis.

Citation Format: Brid M. Ryan, Ana I. Robles, Andrew C. McClary, Elise Bowman, Kirsi Vahakangas, Susan Olivo-Marston, Ping Yang, Jin Jen, Curtis C. Harris. Interaction between DRD1 and childhood exposure to environmental tobacco smoke modulates lung cancer risk in smokers and never smokers. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4581. doi:10.1158/1538-7445.AM2013-4581

Pontine-to-midbrain ratio indexes ocular-motor function and illness stage in adult Niemann-Pick disease type C

BACKGROUND AND PURPOSE

Niemann-Pick disease type C (NPC) is a progressive neurovisceral disorder associated with dystonia, ataxia and a characteristic gaze palsy. Neuropathological studies have demonstrated brainstem atrophy associated with neuronal inclusions and loss, and neurofibrillary tangles, although it is not known whether this pathology can be detected in vivo or how these changes relate to illness variables, particularly ocular-motor changes. Our aim was to utilize a method for brainstem atrophy, validated in progressive supranuclear palsy (PSP), in a group of adult patients with NPC, and explore its relationship to illness variables and ocular-motor functioning.

METHODS

We calculated the midbrain and pontine area, and pontine-to-midbrain ratio (PMR) from midsagittal images of 10 adult patients with NPC and 27 age- and gender-matched controls. Measures were correlated with illness variables, and measures of horizontal saccadic functioning.

RESULTS

Pontine-to-midbrain ratio was 14% higher in the NPC group, but this difference was not significant. However, PMR showed a significant positive correlation with duration of illness and a measure of illness severity. Furthermore, PMR was significantly negatively correlated with saccadic peak velocity and gain, and self-paced saccadic performance.

CONCLUSIONS

Pontine-to-midbrain ratio was increased in adult patients with NPC compared to controls, although not to the same degree as previously described in PSP, which also presents with significant gaze palsy. These changes were driven predominantly by progressive midbrain atrophy. The strong correlation with illness and ocular-motor variables suggests that it may be a useful marker for illness progression in NPC.

Size and shape of the corpus callosum in adult Niemann-Pick type C reflects state and trait illness variables

BACKGROUND AND PURPOSE

Variable alterations to the structure of the corpus callosum have been described in adults with NPC, a neurometabolic disorder known to result in both white and gray matter pathology. This study sought to examine the structure of the callosum in a group of adult patients with NPC and compared callosal structure with a group of matched controls, and to relate callosal structure with state and trait illness variables.

MATERIALS AND METHODS

Nine adult patients with NPC were matched to control subjects (n = 26) on age and sex. The corpus callosum was segmented from the midsagittal section of T1-weighted images on all subjects, and total area, length, bending angle, and mean thickness were calculated. In addition, 39 regional thickness measures were derived by using a previously published method. All measures were compared between groups, and analyzed alongside symptom measures, biochemical parameters, and ocular-motor measures.

RESULTS

The callosal area and mean thickness were significantly reduced in the patient group, and regional thickness differences were greatest in the genu, posterior body, isthmus, and anterior splenium. Global callosal measures correlated significantly with duration of illness and symptom score, and at trend level with degree of filipin staining. Measures of reflexive saccadic peak velocity and gain, and self-paced saccades, correlated strongly with total callosal area.

CONCLUSIONS

Callosal structure and size reflect both state and trait markers in adult NPC, and they may be useful biomarkers to index both white and gray matter changes that reflect illness severity and progression.

Abstract 1171: From genotypes to phenotypes: genetic variation in microRNA-related genes and lung cancer risk

Differential microRNA expression and function has been implicated in a variety of human malignancies. Genetic variation in this network was recently proposed to explain the contribution of this family of non-coding RNAs to cancer. To test this hypothesis in lung cancer in a systematic manner, we collated a list of single nucleotide polymorphisms (SNPs) that lie within pre and mature miRNA genes. We then generated a list of SNPs from 600 genes in loci and pathways with relevance to lung cancer. The 3’ UTR of each of these genes was bioinformatically interrogated for overlap between putative microRNA binding sites and SNPs. The latter could either create or destroy a microRNA binding site and therefore impact protein translation. The SNPs were subsequently analyzed in a study of 300 Caucasian cases and 300 controls.

Odds ratios for lung cancer risk were generated using unconditional logistic analyses and adjusted for age, gender, race, smoking status and pack years of smoking. Our study highlighted a number of novel associations. From our inflammation panel of genes, a SNP in the 3’ UTR of CXCR2 (IL8 receptor) was protective against lung cancer risk (OR: 0.44; 95% C.I. 0.26 – 0.78). As CXCR2 is implicated in oncogene induced senescence, we predict that this SNP gives rise to lower levels of the receptor and are currently testing this possibility both in vitro and in human tissues. Furthermore, a SNP in DRD1 (dopamine receptor DI) is also protective against lung cancer (OR: 0.45; 95% C.I. 0.24 – 0.85), thus intimating that the variant allele gives rise to decreased levels of DRD1 in the brain and therefore a negative re-enforcement of the reward pathway.

Several metabolic genes were implicated from our study, the most notable of which was a SNP in ALDH1A3 (OR: 1.79; 95% C.I. 1.01 – 3.17). Apart from the delineated role in metabolism, this gene is also interesting due to its putative role in lung cancer stem cell biology. Although SNPs in microRNA genes are generally rare, a SNP in miR-585 was significantly associated with an increased risk of lung cancer (OR: 1.69; 95% C.I. 1.10 – 2.59), and most interestingly, the association was strongest for heterozygous carriers. We are currently investigating the effect of the miR-585 SNP on expression of the mature miRNA as well as the role of miR-585 in lung cancer etiology, as nothing is known in this regard at present.

This study is presently being extended to a cohort of African American patients and a nested analysis of never-smokers is also underway. Moreover, we are endeavoring to determine the functional consequences of these epidemiological results and link risk-associated genotypes to oncogenic phenotypes. Our data provides a comprehensive evaluation of the association between genetic variation in the microRNA network and lung cancer risk, and has highlighted several novel associations that may help in our understanding of the genetic basis of lung cancer and the role that microRNAs play.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1171. doi:10.1158/1538-7445.AM2011-1171

Cooperation of tumor-derived HBx mutants and p53-249(ser) mutant in regulating cell proliferation, anchorage-independent growth and aneuploidy in a telomerase-immortalized normal human hepatocyte-derived cell line

Hepatocellular carcinoma (HCC) is a common cancer, and hepatitis B virus (HBV) is a major etiological agent. Convincing epidemiological and experimental evidence also links HCC to aflatoxin, a naturally occurring mycotoxin that produces a signature p53-249(ser) mutation. Recently, we have reported that tumor-derived HBx variants encoded by HBV exhibited attenuated transactivation and proapoptotic functions but retained their ability to block p53-mediated apoptosis. These results indicate that mutations in HBx may contribute to the development of HCC. In this study, we determined whether tumor-derived HBx mutants along, or in cooperation with p53-249(ser), could alter cell proliferation and chromosome stability of normal human hepatocytes. To test this hypothesis, we established a telomerase immortalized normal human hepatocycte line HHT4 that exhibited a near diploid karyotype and expressed many hepatocyte-specific genes. We found that overexpression one of the tumor-derived HBx mutants, CT, significantly increased colony forming efficiency (CFE) while its corresponding wild-type allele CNT significantly decreased CFE in HHT4 cells. p53-249(ser) rescued CNT-mediated inhibition of colony formation. Although HHT4 cells lacked an anchorage independent growth capability as they did not form any colonies in soft agar, the CT-expressing HHT4 cells could form colonies, which could be significantly enhanced by p53-249(ser). Induction of aneuploidy could be observed in HHT4 cells expressing CT, but additionally recurring chromosome abnormalities could only be detected in cells coexpressing CT and p53-249(ser). Our results are consistent with the hypothesis that certain mutations in HBx and p53 at codon 249 may cooperate in contributing to liver carcinogenesis.

Elevated lung cancer risk is associated with deficiencies in cell cycle checkpoints: genotype and phenotype analyses from a case-control study

Cell cycle checkpoints play critical roles in the maintenance of genomic integrity and inactivation of checkpoint genes are frequently perturbed in most cancers. In a case-control study of 299 non-small cell lung cancer cases and 550 controls in Baltimore, we investigated the association between gamma-radiation-induced G(2)/M arrest in cultured blood lymphocytes and lung cancer risk, and examined genotype-phenotype correlations between genetic polymorphisms of 20 genes involving in DNA repair and cell cycle control and gamma-radiation-induced G(2)/M arrest. The study was specifically designed to examine race and gender differences in risk factors. Our data indicated that a less efficient DNA damage-induced G(2)/M checkpoint was associated with an increased risk of lung cancer in African American women with an adjusted odds ratio (OR) of 2.63 (95% CI = 1.01-7.26); there were no statistically significant associations for Caucasians, or African American men. When the African American women were categorized into quartiles, a significant reverse trend of decreased G(2)/M checkpoint function and increased lung cancer risk was present, with lowest-vs.-highest quartile OR of 13.72 (95% CI = 2.30-81.92, p(trend) < 0.01). Genotype-phenotype correlation analysis indicated that polymorphisms in ATM, CDC25C, CDKN1A, BRCA2, ERCC6, TP53, and TP53BP1 genes were significantly associated with the gamma-radiation-induced G(2)/M arrest phenotype. This study provides evidence that a less efficient G(2)/M checkpoint is significantly associated with lung cancer risk in African American women. The data also suggested that the function of G(2)/M checkpoint is modulated by genetic polymorphisms in genes involved in DNA repair and cell cycle control.

Gender dimorphism in siblings with schizophrenia-like psychosis due to Niemann-Pick disease type C

We describe the differential presentation of schizophrenia-like psychosis in two siblings with the 'variant' biochemical presentation of adult Niemann-Pick disease type C. The male sibling presented with psychosis at age 16 years and cognitive and motor disturbance at age 25 years, whereas his elder sister, sharing the same mutation but showing less severe biochemical, neuroimaging and ocular motor parameters, presented with a similar schizophrenia-like illness with associated cognitive and motor disturbance at age 31 years. Their illness onset, course and response to treatment mirrors the sex dimorphism seen in schizophrenia, and is suggestive of an interaction between the neurobiology of their metabolic disorder and sex differences in neurodevelopment.

Chemotherapy-free interval following initial chemotherapy in patients with stage IV colorectal cancer

e15096

Background: Patients with metastatic colorectal cancer (mCRC) have improved survival due to recent advances in systemic therapy. It remains unclear whether patients responding to initial chemotherapy can be offered a chemotherapy free interval (CFI) without compromising survival. An initial CFI is potentially beneficial from a quality of life and health care economics standpoint. Methods: We studied patients with mCRC treated at Baylor University Medical Center (Dallas, TX) who had a CFI after first-line chemotherapy. Eligible patients had unresectable mCRC and had stable or responding disease after initial chemotherapy. Records were analyzed to record patient characteristics, chemotherapy details, initial response, duration of CFI, progression free survival (PFS), and overall survival (OS). Results: We identified 29 eligible patients treated between 11/02 and 11/08. Analyses are based on data from 8/08. Patient characteristics included: median age 63 (range 34–81), M/F 16/13, ECOG PS 0 (9) or 1 (20), and median number of sites of disease 2 (range 1–7). Initial chemotherapy regimens included mFOLFOX6 with or without bevacizumab (10), FOLFIRI/bevacizumab (12), XELOX/bevacizumab (2), 5-fluorouracil/leucovorin/bevacizumab (3), and capecitabine with or without bevacizumab (2). With a median follow-up of 31.1 months, the median duration of CFI was 8.0 months (95% CI: 4.3–9.6). In addition, the median OS was 33.7 months (95% CI: 27.8 -56.3) and PFS was 15.0 months (95% CI: 9.4–21.4). Conclusions: In this selected group of patients with mCRC, we found a CFI of 8 months. The OS nearing 34 months and PFS of 15 months compares favorably with other studies of patients treated for mCRC. An initial CFI may reduce the medical and financial burden of therapy for patients with mCRC without compromising outcomes and warrants further study.

[Table: see text]

Unique microRNA molecular profiles in lung cancer diagnosis and prognosis

MicroRNA (miRNA) expression profiles for lung cancers were examined to investigate miRNA's involvement in lung carcinogenesis. miRNA microarray analysis identified statistical unique profiles, which could discriminate lung cancers from noncancerous lung tissues as well as molecular signatures that differ in tumor histology. miRNA expression profiles correlated with survival of lung adenocarcinomas, including those classified as disease stage I. High hsa-mir-155 and low hsa-let-7a-2 expression correlated with poor survival by univariate analysis as well as multivariate analysis for hsa-mir-155. The miRNA expression signature on outcome was confirmed by real-time RT-PCR analysis of precursor miRNAs and cross-validated with an independent set of adenocarcinomas. These results indicate that miRNA expression profiles are diagnostic and prognostic markers of lung cancer.

Circulating clonal CLA(+) and CD4(+) T cells in Sezary syndrome express the skin-homing chemokine receptors CCR4 and CCR10 as well as the lymph node-homing chemokine receptor CCR7

BACKGROUND

Adhesion molecules and chemokine receptors are involved in tissue-specific homing of T cells to the skin and play an important role in the pathophysiology of cutaneous lymphoma. It has recently been reported that the chemokine CCL27 expressed by keratinocytes attracts lymphocytes bearing the chemokine receptor CCR10.

OBJECTIVES

To investigate the expression of CCR4, CCR7 and CCR10 on skin-homing CLA(+) and CD4(+) T cells in the peripheral blood of patients with Sezary syndrome (SS), a rare leukaemic variant of cutaneous T-cell lymphoma.

METHODS

Lymphocytes from five patients with SS, six patients with mycosis fungoides and four healthy volunteers were isolated and analysed using flow cytometry. Additionally, the T-cell receptor (TCR)-Vbeta CDR3 regions were cloned and sequenced in two patients.

RESULTS

We found that CCR4 is expressed on almost all CLA(+) and CD4(+) memory T cells. Using monoclonal antibodies specific for single TCR-Vbeta chains we identified malignant T cells in four patients with SS. Importantly, we found that most but not all malignant Sezary cells expressed the skin-homing chemokine receptor CCR10. Additionally, we found that a significant proportion of these cells also expressed the lymph node-homing chemokine receptor CCR7.

CONCLUSIONS

Our results support the concept that chemokine receptors play an important role in the pathophysiology of SS and suggest that the malignant clone may represent an expansion of skin-homing cutaneous 'central' memory T cells in the peripheral blood of these patients.

Diet and alcohol consumption in relation to p53 mutations in breast tumors

There is evidence linking alcohol consumption to p53 mutations in tumors, considerable evidence linking alcohol consumption with risk of breast cancer and some evidence that alcohol and folate consumption interact to affect risk. Further, while there is some indication that oxidation may play a role in breast cancer etiology, there has been little examination of an association of oxidative stress with p53 mutations. We examined several dietary components related to one-carbon metabolism and antioxidants to determine if these factors were related to the prevalence of p53 mutations in breast tumors. We conducted a case-control study of primary, histologically confirmed breast cancer in western New York. Controls <65 were selected from drivers license lists; those > or =65 were selected from Health Care Finance Administration lists. p53 mutations in archived tumor blocks were identified in exons 2-11 and flanking intron sequences. Usual dietary intake was assessed by interview regarding intake in the previous 2 years; alcohol consumption was queried for 2, 10 and 20 years in the past. Our data were consistent with increased likelihood of tumors with p53 mutations for premenopausal breast cancer with increased alcohol intake 10 or 20 years previous; for intake of 16 or more drinks per month in the period 20 years before the interview compared with non-drinkers, the OR was 5.25, 95% CI 1.48-18.58. For postmenopausal women, there was increased likelihood of tumors with p53 mutations among women with higher folate. Antioxidant nutrients were not differentially related to p53 mutations. These results indicate that there may be heterogeneity in breast tumors, as indicated by differences in associations for those with or without p53 mutations, and that causal pathways for these nutrients may vary for pre- and postmenopausal women. For premenopausal women, alcohol consumption in the past was associated with p53 mutations.

Suggestive evidence of a locus on chromosome 10p using the NIMH genetics initiative bipolar affective disorder pedigrees

As part of a four-center NIMH Genetics Initiative on Bipolar Disorder, a genome screen using 365 markers was performed on 540 DNAs from 97 families, enriched for affected relative pairs. This is the largest uniformly ascertained and assessed linkage sample for this disease, and includes 232 subjects diagnosed with bipolar I (BPI), 32 with schizo-affective, bipolar type (SABP), 72 with bipolar II (BPII), and 88 with unipolar recurrent depression (UPR). A hierarchical set of definitions of affected status was examined. Under Model I, affected individuals were those with a diagnosis of BPI or SABP, Model II included as affected those fitting Model I plus BPII, and Model III included those fitting Model II plus UPR. This data set was previously analyzed using primarily affected sib pair methods. We report the results of nonparametric linkage analyses of the extended pedigree structure using the program Genehunter Plus. The strongest finding was a lod score of 2.5 obtained on chromosome 10 near the marker D10S1423 with diagnosis as defined under Model II. This region has been previously implicated in genome-wide studies of schizophrenia and bipolar disorder. Other chromosomal regions with lod scores over 1.50 for at least one Model Included chromosomes 8 (Model III), 16 (Model III), and 20 (Model I). Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:18-23, 2000

Changing mortality and causes of death in infants 23-27 weeks' gestational age

OBJECTIVE

To contrast the mortality rates and changes in the causes of death of very preterm infants (23-27 weeks), before and after the introduction of exogenous surfactant in 1991, and to identify any preventable causes of death remaining in the 1990s.

METHODOLOGY

This was a cohort study on consecutive preterm infants of 23-27 weeks' gestational age born in the Royal Women's Hospital, Melbourne, a level III perinatal centre. The infants were livebirths free of lethal anomalies from two distinct eras, 1983-90, and 1992-96, inclusive. The main outcome measures were mortality during the primary hospitalization and the causes of death before and after the introduction of exogenous surfactant in 1991.

RESULTS

In 1983-90, 261 of 508 livebirths (51.4%) of 23-27 weeks' gestational age died, a significantly higher proportion than the 109 of 384 (28.4%) livebirths who died in the period 1992-96. The mortality rate fell significantly with increasing gestational age and was lower at each week of gestational age in 1992-96. More infants who died in 1992-96 were treated intensively in the neonatal intensive care unit (NICU). Of the group of infants who died or who were treated intensively in NICU, respiratory causes of death predominated. However, the causes of death changed over time. In 1992-96 proportionally fewer infants died from respiratory causes (1983-90, 82.5%; 1992-96, 60.0%; odds ratio (OR) 0.31, 95%; confidence interval (CI) 0.16-0.57), but more from septic causes (1983-90, 14.3%; 1992-96, 43.8%; OR 4.9, 95%; CI 2.6-9.2).

CONCLUSIONS

As the mortality rate has fallen over time, respiratory causes of death have diminished, but septic causes of death have increased. Further advances in the use of exogenous surfactant and respiratory support may reduce respiratory deaths. Effective strategies to reduce nosocomial infections are urgently required.

Manganese superoxide dismutase (MnSOD) genetic polymorphisms, dietary antioxidants, and risk of breast cancer

Oxidative stress, resulting from the imbalance between prooxidant and antioxidant states, damages DNA, proteins, cell membranes, and mitochondria and seems to play a role in human breast carcinogenesis. Dietary sources of antioxidants (chemical) and endogenous antioxidants (enzymatic), including the polymorphic manganese superoxide dismutase (MnSOD), can act to reduce the load of oxidative stress. We hypothesized that the valine-to-alanine substitution that seems to alter transport of the enzyme into the mitochondrion, changing its efficacy in fighting oxidative stress, was associated with breast cancer risk and that a diet rich in sources of antioxidants could ameliorate the effects on risk. Data were collected in a case-control study of diet and breast cancer in western New York from 1986 to 1991. Caucasian women with incident, primary, histologically confirmed breast cancer were frequency-matched on age and county of residence to community controls. Blood specimens were collected and processed from a subset of participants in the study (266 cases and 295 controls). Using a RFLP that distinguishes a valine (V) to alanine (A) change in the -9 position in the signal sequence of the protein for MnSOD, we characterized MnSOD genotypes in relation to breast cancer risk. We also evaluated the effect of the polymorphism on risk among low and high consumers of fruits and vegetables. Premenopausal women who were homozygous for the A allele had a 4-fold increase in breast cancer risk in comparison to those with 1 or 2 V alleles (odds ratio, 4.3; 95% confidence interval, 1.7-10.8). Risk was most pronounced among women below the median consumption of fruits and vegetables and of dietary ascorbic acid and alpha-tocopherol, with little increased risk for those with diets rich in these foods. Relationships were weaker among postmenopausal women, although the MnSOD AA genotype was associated with an almost 2-fold increase in risk (odds ratio, 1.8; confidence interval, 0.9-3.6). No appreciable modification of risk by diet was detected for these older women. These data support the hypothesis that MnSOD and oxidative stress play a significant role in breast cancer risk, particularly in premenopausal women. The finding that risk was greatest among women who consumed lower amounts of dietary antioxidants and was minimal among high consumers indicates that a diet rich in sources of antioxidants may minimize the deleterious effects of the MnSOD polymorphism, thereby supporting public health recommendations for the consumption of diets rich in fruits and vegetables as a preventive measure against cancer.

Preterm infants 30-36 weeks' gestation in Victoria--where should they be delivered?

There is little doubt that very preterm infants <30 weeks' gestation should be born in level-3 perinatal centres. For preterm infants 30-36 weeks' gestation, however, the optimum place of birth is not so clear-cut. The aims of this study of livebirths 30-36 weeks' gestational age born in Victoria were to determine: 1) the proportions delivered outside level-3 centres, and 2) for infants born outside level-3 centres, the proportions transferred after birth to a level-3 nursery in the first days after birth. Data on the number of livebirths 30-36 weeks' gestational age in Victoria in the 3 years 1994-1996, inclusive, were supplied by the Victorian Perinatal Data Collection Unit. Data were obtained from the Newborn Emergency Transport Service (NETS) on all transfers within the first 3 days after birth to a level-3 centre for infants born outside level-3 centres. For the 3 years 1994-1996 there were 11,375 livebirths 30-36 weeks' gestational age in Victoria. The proportion born outside a level-3 perinatal unit was 57.9% overall, and rose with increasing gestational age, from 10.9% at 30 weeks to 69.0% at 36 weeks. Of the 6,587 livebirths outside a level-3 centre, 808 (12.3%) were transferred within the first 3 days after birth by NETS to a level-3 centre, the proportions falling with increasing maturity, being 73.7%, 48.5%, 28.4%, 26.9%, 18.8%, 11.8%, and 7.0% at 30, 31, 32, 33, 34, 35, and 36 weeks, respectively. These data may help medical practitioners when determining the place of delivery for infants 30-36 weeks' gestation.

Disproportionate consumption of ventilator resources by very preterm survivors persists in the 1990s

The aim of this study of consecutive livebirths between 23 and 30 weeks of gestational age was to determine the changes over time in the relationship between gestational age and the consumption of nursery resources by surviving preterm infants. Three discrete eras, comprising the years 1977-1985, 1986-1990, and 1991-1995, were identified, based on availability of ventilators and changes in perinatal care. The survival rate rose dramatically with each week's increase in gestational age, and increased significantly between successive eras. Overall, consumption of resources for assisted ventilation by survivors increased over time. In infants born before 28 weeks, for each week of decrease in gestational age, survivors averaged an extra 12.9 days of assisted ventilation in 1977-1985, 13.4 days in 1986-1990, and 13.5 days in 1991-1995, while infants born between 28-30 weeks of gestational age needed only an extra 2.3 days, 3.3 days, and 4.6 days of assisted ventilation for each week of decrease in gestational age in successive eras, respectively. There was no indication that improvements in perinatal care over time shortened the duration of assisted ventilation for surviving preterm infants.

Initial genomic scan of the NIMH genetics initiative bipolar pedigrees: chromosomes 3, 5, 15, 16, 17, and 22

As part of the four-center NIMH Genetics Initiative on Bipolar Disorder we carried out a genomic scan of chromosomes 3, 5, 15, 16,17, and 22. Genotyping was performed on a set of 540 DNAs from 97 families, enriched for affected relative pairs and parents where available. We report here the results of the initial 74 markers that have been typed on this set of DNAs. The average distance between markers (theta) was 12.3 cM. Nonparametric analysis of excess allele sharing among affected sibling pairs used the SIBPAL program of the S.A.G.E. package to test three hierarchical models of affected status. D16S2619 gave some evidence of linkage to bipolar disorder, with P = 0.006 for Model II (in which bipolar 1, bipolar 2 and schizoaffective-bipolar type individuals are considered affected). Nearby markers also showed increased allele sharing. A second interesting region was toward the telomere of chromosome 5q, where D5S1456 and nearby markers showed increased allele sharing; for D5S1456, P = 0.05, 0.015 and 0.008 as the models of affected status become more broad. MOD score analysis also supported the possible presence of a susceptibility locus in this region of chromosome 5. A pair of adjacent markers on chromosome 3, D3S2405 and D3S3038, showed a modest increased allele sharing in the broad model. Several isolated markers had excess allele sharing at the P < 0.05 level under a single model. D15S217 showed a MOD score of 2.37 (P < 0.025). Multipoint analysis flagged the region of chromosome 22 around D22S533 as the most interesting. Thus, several regions showed modest evidence for linkage to bipolar disorder in this initial genomic scan of these chromosomes, including broad regions near previous reports of possible linkage.

Chromosome 13 poly(ADP-ribose) polymerase polymorphisms and lung cancer risk

A 193 base pair repeat polymorphism in the human poly(ADP-ribose) polymerase (PADPRP) pseudogene found on chromosome 13 has been associated with lung cancer, endemic Burkitt lymphoma, B-cell lymphoma, breast cancer and colorectal carcinoma. We investigated the frequency of the PADPRP genetic polymorphism in a hospital-based case-control study of lung cancer for 54 cases and 47 controls. There was a statistically significant difference in allelic frequency between Caucasians and African Americans (p<0.001). For African Americans, the odds ratio for lung cancer and the 'B' allele was 2.38 (95% C.I.=0.73, 7.69) and for Caucasians 0.44 (95% C.I.=0.11, 1.77). The results for the African Americans, however, were not in Hardy-Weinberg equilibrium, although the Caucasians were. Thus, this study, albeit small, does not find that the PADPRP pseudogene duplicated region located on chromosome 13 is a risk factor for lung cancer.

Changes over time in attitudes to treatment and survival rates for extremely preterm infants (23-27 weeks' gestational age)

We determined the changes over time in attitude to treatment of very preterm infants (23-27 weeks of gestational age) born at the Royal Women's Hospital, Melbourne, and their survival rate. The subjects were consecutive livebirths at 23-27 weeks' gestational age born from 1983-1994, inclusive. The main outcomes measured were the proportions of livebirths treated intensively and survival rates to hospital discharge, both excluding lethal abnormalities. Over the 12 years of the study there were 788 livebirths free of lethal abnormalities born at 23-27 week's gestational age. Overall 669 (85%) were treated intensively; the proportions treated intensively rose significantly over time from 74% in 1983-1985 to 91% in 1992-1994, and with increasing gestational age, from 19% at 23 weeks to 100% at 27 weeks. Overall 439 (56%) survived their primary hospitalization; the survival rate rose significantly over time, from 43% in 1983-1985 to 70% in 1992-1994, and with increasing gestational age, from 3% at 23 weeks to 78% at 27 weeks. In 1992-1994, the survival rates were 11% at 23 weeks, 53% at 24 weeks, 70% at 25 weeks, 81% at 26 weeks, and 87% at 27 weeks. For infants treated intensively, the survival rate rose significantly from 53% in 1983-1985 to 76% in 1992-1994. The largest increases in survival have occurred in the 1990s, and at 24 and 25 weeks' gestational age. The proportions of very preterm infants treated intensively and their survival rates have increased over time, and have always been higher with increasing gestational age.

Zipeprol: preclinical assessment of abuse potential

Zipeprol was evaluated in a number of in vitro and in vivo assays predictive of stimulant, depressant, or opioid abuse potential. Zipeprol had affinity for mu and kappa opioid binding sites as well as sigma binding sites. However, it failed to exert opioid-like agonist actions in rodents, and did not attenuate withdrawal signs in morphine- or pentobarbital-dependent rats. Zipeprol did not substitute for either amphetamine or pentobarbital in drug discrimination assays in rhesus monkeys. On the other hand, it suppressed morphine withdrawal signs in rhesus monkeys in two assays, and it acted as a quadazocine-sensitive reinforcer in monkeys trained to self-inject alfentanil. Zipeprol also acted as a reinforcer in monkeys trained to self-inject methohexital. In a dose range of 10-18 mg/kg, zipeprol induced convulsions in monkeys. Zipeprol appears to have abuse potential and a novel spectrum of action involving both opioid and non-opioid effects.

Assisted ventilation and survival of extremely low birthweight infants

OBJECTIVE

To determine the incremental consumption of ventilator resources associated with the improving survival rate of extremely low birthweight (ELBW birthweight 500-999g) infants, from the time assisted ventilation was introduced.

METHODOLOGY

Cohort study of ELBW infants born in one tertiary perinatal centre (The Royal Women's Hospital, Melbourne). All ELBW infants born from 1971 to 1993 were included in the study. In hospital survival rates and patient-days of assisted ventilation were the main outcome measures. Discrete eras of relatively stable survival rate and consumption of ventilator resources were identified. These comprised the years 1971-74, 1977-83, 1985-90, and 1992-93. Cost-effectiveness ratios (the incremental consumption of ventilator resources per additional survivor) were calculated between adjacent eras by dividing the increment in the consumption of ventilator resources by the increment in the survival rate.

RESULTS

The survival rates rose progressively between eras (6.2, 33.9, 49.1, 68.8%, respectively, as did the consumption of ventilator resources (0.1, 6.6, 16.2, 24.7 patient-days of assisted ventilation per livebirth, respectively). The cost-effectiveness ratio deteriorated initially, increasing from 23.2 to 63.5 additional patient-days of assisted ventilation per additional survivor, but then improved, falling to 43.1 additional patient-days of assisted ventilation per additional survivor in the last era. These changes were even more marked for those of birthweight 750-999g (20.0, 63.2 to 35.9 additional patient-days of assisted ventilation per additional survivor, respectively). In contrast, the cost-effectiveness ratio was initially worse for those of birthweight 500-749 g, being three-fold higher than for the larger infants, and only improved substantially in the last era (59.8, 58.3 to 44.1 additional patient-days of assisted ventilation per additional survivor, respectively).

CONCLUSIONS

The initial deterioration in cost-effectiveness ratios between successive eras probably reflected the increased availability of resources for assisted ventilation, without any other major advances in perinatal care. The improvement in cost-effectiveness in the last era reflected, in part, the increased use of antenatal steroid therapy and the introduction of exogenous surfactant to neonatal intensive care.

Erythrocyte membrane structure in bipolar affective disorder: a non-replication

Fifteen bipolar patients were compared with sixteen controls in an attempt to replicate the findings of Pettegrew et al. in 1982 of decreased fluidity in the hydrocarbon core of the erythrocyte membrane. No significant differences were seen between groups. The present control group shows very similar membrane characteristics to the original control series; however, the bipolar patient group is not similar. Possible explanations are discussed.

The cost of improving the outcome for infants of birthweight 500-999 g in Victoria. The Victorian Infant Collaborative Study Group

The aim of this study was to conduct an economic evaluation of neonatal intensive care for extremely low birthweight (ELBW) infants born in the state of Victoria. Two distinct eras (1979-80 and 1985-87) were compared. Follow-up data at 2 years of age were available for all 89 survivors from the 351 live births in 1979-80, and for 211 of 212 survivors from the 560 live births in 1985-87. The overall cost-effectiveness for ELBW infants during 1985-87 compared with 1979-80 was $104,990 ($A 1987) per additional survivor, or $5390 ($A 1987) per additional life year gained. Cost-effectiveness improved with increasing birthweight. If the quality of life of the survivors was considered, the economic outlook was more favourable. The cost per quality-adjusted life year gained was $5090 ($A 1987), approximately one-tenth of that obtained from the only previous full economic evaluation of neonatal intensive care. Although neonatal intensive care is expensive, it compares favourably with some other health care programmes, particularly as the outcome for ELBW infants continues to improve.

The teaching of health statistics: meeting the needs of a changing practice

The findings of the study did support the faculty's hypotheses. First, only 50% of the hospitals retain responsibility for the statistical function. This finding was, however, affected by the size of the hospital, with 100% of the hospitals of 400 beds or less retaining such responsibility. Second, the findings showed that only 12.5% of the hospitals had entirely manual statistical systems. However, 50% of the hospitals did compile some statistics manually, including the daily hospital census and discharge service statistics. Finally, in looking at the UT Memphis statistics curriculum and those of 14 other medical record administration programs in the Southeast, the hypothesis that curricula did not mirror this changing practice was confirmed. Although 100% of the programs surveyed had students memorize statistical formulas, only 36% had students working with computers in the statistics course. Of the 14 programs, only 6 specifically covered QA of statistical data in the statistics course, and 9 did not deal at all with how to assess the adequacy of policies and procedures for gathering statistical information. As a result of these findings, UT Memphis has modified its statistical course to increase the emphasis on computerization, QA, and assessment of statistical policies and procedures. These changes will better prepare the UT Memphis graduate for the statistical responsibilities that they will face in the workplace.

Continuing morbidity in extremely low birthweight infants

The pattern of lesser but continuing morbidity in the first 2 years was reported in 36 survivors who weighed 500-799 g at birth and in 83 survivors who weighed 800-999 g at birth. Over this period, there was one post-discharge death. Sixty-one percent of children were rehospitalized, most commonly for respiratory tract disorders and surgical procedures such as aural ventilation tube insertion and inguinal herniorrhaphy. Their three most common medical disorders were otitis media (55%), wheezing episode (48%) and lower respiratory tract infection (29%). At 2 years of age, 44% remained below the tenth percentile for weight, 45% for height and 12% for head circumference. Other lesser morbidity included iatrogenic scarring, abnormal head shape and behavioural problems. Except for otitis media, survivors of 500-799 g birthweight did not have a significantly higher rate of neurodevelopmental impairment, health problems, rehospitalization, suboptimal growth or behavioural disorders, compared to those of 800-999 g birthweight. This study confirms the need for providing extremely low birthweight children and their families with a continuity of comprehensive medical care and social support after hospital discharge.

Increased mortality of preterm infants transferred between tertiary perinatal centres

Over 18 months almost one quarter of infants born before 30 weeks' gestation in a tertiary perinatal centre who required intensive care had to be transferred to other tertiary centres because intensive care facilities were fully occupied. When infants with lethal congenital malformations were excluded half of the 34 infants who were transferred died; this was twice the mortality (24%) in the 111 infants remaining. The difference between the groups was significant (relative odds = 3.1) and remained so after adjustment for any discrepancies in gestational age (relative odds = 4.0). After adjustment for potential confounding variables by logistic function regression the risk of dying for those transferred remained significantly higher than that for infants who remained (relative odds = 4.6, 95% confidence interval 1.8 to 12.1). As the requirement for neonatal intensive care is episodic and unpredictable more flexibility has to be built into the perinatal health care system to enable preterm infants delivered in tertiary perinatal centres to be cared for where they are born.

Elucidation of the 2-aminoethylphosphonate biosynthetic pathway in Tetrahymena pyriformis

The biosynthetic reaction pathway leading to the natural product, 2-aminoethylphosphonate in Tetrahymena pyriformis has been elucidated. Incubation of [32P]PEP and [14C]PEP with T.pyriformis cellular homogenate fortified with Mg2+ and alanine/pyridoxal phosphate, yielded 2-aminoethylphosphonate as the minor reaction product (2-5% yield) and phosphoglycerate and pyruvate plus orthophosphate as the major products. Inclusion of thiamine pyrophosphate in the reaction mixture increased the yield of 2-aminoethylphosphonate by a factor of 10. Incubation of phosphonoacetaldehyde or phosphonopyruvate in the cellular homogenate also provided 2-aminoethylphosphonate. The cellular homogenate catalyzed the transformation of phosphonoacetaldehyde to 2-aminoethylphosphonate in an ca. 80% yield. However, the maximum yield of 2-aminoethylphosphonic acid obtained by use of phosphonopyruvate was only 15%. The major reaction pathways induced by treatment of phosphonopyruvate with the cellular extract involved its competitive conversion to PEP and pyruvate plus orthophosphate.