Reference the seabed topographic depth observations based on the national mean dynamic topography model

The mean sea surface in different regions is non-equipotential, rendering Vietnam's traditional approach, which relies on the Hon-Dau tide gauge station as a reference, not yet scientifically invalid. To overcome this, our study utilized the Vietnam national mean dynamic topography model (MDTVN22) for depth observations, particularly in the Gulf of Tonkin. Covering 3430 monitoring sites in Hai Phong and 813 sites in Quang Ninh, our experiments highlighted a 5 to 6 mm difference between the mean sea surface and MDTVN22 references. •Our research establishes a resilient methodology, integrating shore tide gauge station data and the MDTVN22 model, aimed at enhancing precision in depth observations.•Validation experiments in Hai Phong demonstrate a minimal discrepancy of ±0.006 m between measurements obtained from the traditional mean sea surface and the MDTVN22 model.•These findings underscore the significance of adopting the MDTVN22 model for improved accuracy in assessing Vietnam's seabed topography.

Potential tools for predicting response to chemotherapy in OC: Assessment of immune dysbiosis, participant's self-rated health and microbial dynamics

Epithelial ovarian cancer (OC) is the deadliest female reproductive cancer; an estimated 13,270 women will die from OC in 2023. Platinum-based chemotherapy resistance mechanisms contribute to poor OC 5-year survival rates. Peripheral inflammation is linked to various disease states and we previously identified unique peritoneal microbial features predictive of OC. We hypothesized that unique peripheral immune profiles and peritoneal microbial features may be predictive of disease-free interval (time to recurrence) and response to chemotherapy in participants with OC. We also investigated self-rated health (SRH) scores in the context of peripheral inflammation as a potential screening tool for OC. Blood and peritoneal fluid were collected from participants with OC or a benign adnexal mass (BPM). Lymphocyte populations were analyzed using Fluorescence Activated Cell Sorting, serum cytokine levels were analyzed using the Human Th17 Magnetic Bead Panel assay and peritoneal fluid microbial features were analyzed using Next Generation Sequencing (NGS). Participants completed a standardized questionnaire on self-rated physical and emotional health. Participants were classified into three chemotherapy response categories: platinum-refractory, platinum-resistant or platinum-sensitive. A significant positive correlation was found between elevated inflammatory status on the day of surgery and longer disease-free interval. SRH measures did not correlate with immune status in participants with OC or a BPM. We identified a correlation between peritoneal microbial features and chemotherapy response. We conclude that immune dysbiosis may be useful in predicting OC recurrence. The immune findings reported here set the framework for additional studies utilizing immune profiles to predict platinum-based chemotherapy responsiveness in OC.

A dedicated cytoplasmic container collects extrachromosomal DNA away from the mammalian nucleus

Expression from transfected plasmid DNA is generally transient, but it is unclear what process terminates it. We show that DNA entering mammalian cells is rapidly surrounded by a double membrane in the cytoplasm, in some cases after leaving the nucleus. This cytoplasmic container, termed exclusome, frequently also contains extrachromosomal telomeric DNA, and is maintained by the cell over several division cycles. The exclusome envelope contains endoplasmic reticulum proteins and the inner-nuclear membrane proteins Lap2β and Emerin, but differs from the nuclear envelope by its fenestrations and the absence of the Lamin B Receptor and nuclear pore complexes. Reduction of exclusome frequency upon overexpressing Emerin's LEM-domain suggests a role for Emerin in plasmid DNA compartmentalization. Thus, cells distinguish extrachromosomal DNA and chromosomes and wrap them into similar yet distinct envelopes keeping the former in the exclusome but the latter in the nucleus, where transcription occurs.

DNA replication initiation factor RECQ4 possesses a role in antagonizing DNA replication initiation

Deletion of the conserved C-terminus of the Rothmund-Thomson syndrome helicase RECQ4 is highly tumorigenic. However, while the RECQ4 N-terminus is known to facilitate DNA replication initiation, the function of its C-terminus remains unclear. Using an unbiased proteomic approach, we identify an interaction between the RECQ4 N-terminus and the anaphase-promoting complex/cyclosome (APC/C) on human chromatin. We further show that this interaction stabilizes APC/C co-activator CDH1 and enhances APC/C-dependent degradation of the replication inhibitor Geminin, allowing replication factors to accumulate on chromatin. In contrast, the function is blocked by the RECQ4 C-terminus, which binds to protein inhibitors of APC/C. A cancer-prone, C-terminal-deleted RECQ4 mutation increases origin firing frequency, accelerates G1/S transition, and supports abnormally high DNA content. Our study reveals a role of the human RECQ4 C-terminus in antagonizing its N-terminus, thereby suppressing replication initiation, and this suppression is impaired by oncogenic mutations.

Association of microbial dynamics with urinary estrogens and estrogen metabolites in patients with endometriosis

Endometriosis is an estrogen dependent gynecological disease associated with altered microbial phenotypes. The association among endogenous estrogen, estrogen metabolites, and microbial dynamics on disease pathogenesis has not been fully investigated. Here, we identified estrogen metabolites as well as microbial phenotypes in non-diseased patients (n = 9) and those with pathologically confirmed endometriosis (P-EOSIS, n = 20), on day of surgery (DOS) and ~1–3 weeks post-surgical intervention (PSI). Then, we examined the effects of surgical intervention with or without hormonal therapy (OCPs) on estrogen and microbial profiles of both study groups. For estrogen metabolism analysis, liquid chromatography/tandem mass spectrometry was used to quantify urinary estrogens. The microbiome data assessment was performed with Next generation sequencing to V4 region of 16S rRNA. Surgical intervention and hormonal therapy altered gastrointestinal (GI), urogenital (UG) microbiomes, urinary estrogen and estrogen metabolite levels in P-EOSIS. At DOS, 17β-estradiol was enhanced in P-EOSIS treated with OCPs. At PSI, 16-keto-17β-estradiol was increased in P-EOSIS not receiving OCPs while 2-hydroxyestradiol and 2-hydroxyestrone were decreased in P-EOSIS receiving OCPs. GI bacterial α-diversity was greater for controls and P-EOSIS that did not receive OCPs. P-EOSIS not utilizing OCPs exhibited a decrease in UG bacterial α-diversity and differences in dominant taxa, while P-EOSIS utilizing OCPs had an increase in UG bacterial α-diversity. P-EOSIS had a strong positive correlation between the GI/UG bacteria species and the concentrations of urinary estrogen and its metabolites. These results indicate an association between microbial dysbiosis and altered urinary estrogens in P-EOSIS, which may impact disease progression.

Trial leadership by women is associated with racial diversity among heart failure clinical trial participants: a systematic bibliometric review 2000–2020

Background

For the results of randomized controlled trials (RCTs) to be generalizable, they should report on and include the broad range of patients who have the disease.

Purpose

We assessed temporal trends and trial factors associated with 1) the reporting of race or ethnicity data and 2) the enrolment of Black, Indigenous, and people of colour (BIPOC) in Heart Failure (HF) RCTs.

Methods

We searched MEDLINE, EMBASE, and CINAHL for RCTs that recruited adults with HF and were published in journals with an impact factor ≥10 between January 1, 2000 and June 17, 2020. We extracted data in duplicate and used the Cochran-Armitage and Jonchkeere-Terpstra tests to examine temporal trends. We used multivariable regression to assess the independent association between trial factors and the outcomes of interest.

Results

A total of 414 RCTs met inclusion criteria, of which a vast majority (90.6%; 95% CI 87.4–93.2%) were coordinated in either Europe or North America. Only 157 of the 414 RCTs (37.9%; 95% CI 33.2–42.8%) reported race/ethnicity data; among the 158,200 participants in these trials, only 29,512 (18.7%; 95% CI 18.5–18.9%) were BIPOC. There was a significant increase in the reporting of race or ethnicity data (from 26.9% in 2000–2001 to 54.2% in 2019–2020, p<0.001) and in enrollment of BIPOC (from 16.5% in 2000–2001 to 23.9% in 2019–2020, p=0.038) between 2000–2020. Trial leadership by a woman was associated with twice the adjusted odds of reporting of race or ethnicity data (OR 2.0; 95% CI 1.1–3.8; p=0.028) and an 8.4% (95% CI 1.9–15.0%; p=0.012) adjusted increase in enrollment of BIPOC. The race/ethnicity of trial leaders was not available for analysis.

Conclusions

Among HF RCTs published between 2000–2020, <38% reported data on race or ethnicity, although this increased over time. Among trials reporting such data, <19% of participants were BIPOC, with modest increases in enrollment over time. Trials led by women had greater adjusted odds of reporting race/ethnicity data and enrollment of BIPOC.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): CIHR

Temporal trends in the inclusion of patient-reported outcomes in heart failure randomized trials published in high-impact medical journals: a systematic bibliometric review

Background

Patient reported outcomes (PROs) are important measures of health, particularly in symptomatic conditions such as heart failure (HF), and regulatory agencies have encouraged their collection in randomized controlled trials (RCTs).

Purpose

To assess temporal trends in the inclusion of patient-reported outcomes (PROs) in heart failure (HF) randomized controlled trials (RCTs) published in high-impact medical journals, explore trial characteristics associated with inclusion of PROs, and describe the quality of PRO reporting in HF RCTs.

Methods

We searched MEDLINE, EMBASE and CINAHL for studies published between January 1, 2000 and July 17, 2020. We included RCTs published in journals with impact factor ≥10. We assessed temporal trends using the Jonckheere-Terpstra test and conducted multivariable logistic regression analysis to explore trial characteristics independently associated with inclusion of PROs. We assessed the quality of PRO reporting using the Consolidated Standards for Trial Reporting PRO extension statement.

Results

We identified 12,342 articles, of which 417 RCTs met inclusion criteria. PROs were included in 224 RCTs (53.7%, 95% confidence interval [CI]: 48.8%-58.6%), of which 44 (19.6%) reported PRO as primary or co-primary endpoint. The proportion of RCTs with PROs increased significantly between 2000–2003 (37.4%) and 2016–2020 (65.1%) (p<0.001). PROs had higher odds of inclusion in RCTs that were multicenter (odds ratio [OR]: 1.95; 95% CI: 1.05–3.64; p=0.036); medium-sized (n=51–250) (OR: 2.29; 95% CI: 1.24–4.23; p=0.008); coordinated in in Central and South America (OR: 6.79; 95% CI: 1.34–34.36; p=0.021); and assessed health services (OR: 4.21; 1.97–8.98; p<0.001), device / surgical (OR: 6.24; 95% CI 3.05–12.80; p<0.001), or exercise and rehabilitation interventions (OR: 3.98; 95% CI 1.59–9.97; p=0.003). A majority (54.9%) of the 224 RCTs reported four or less of the eleven CONSORT-PRO items. The median number of CONSORT-PRO items reported was 4 (interquartile range [IQR] 3–6 items per trial), with improved reporting in trials with PRO as primary or co-primary endpoint.

Conclusions

PROs are included in in just over half of HF RCTs, with an increased reporting of PROs between 2000 and 2020. Large, pharmacotherapy trials conducted in North America and Europe were less likely to include PROs. The quality of PRO reporting in HF RCTs was modest, with trials most often reporting four of eleven CONSORT-PRO items.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Canadian Institutes of Health Research

Global representation of heart failure clinical trial leaders and collaborators: a systematic bibliometric review 2000–2020

Aims

Heart Failure (HF) has a disproportionate burden in low- and middle-income countries. The geographic representation of those who lead HF randomized clinical trials (RCTs) may not reflect the geographic burden of disease. We assessed temporal trends and trial characteristics associated with leadership outside Europe and North America, and explored whether there was a geographic association between trial leadership and participant enrolment.

Methods and results

We searched MEDLINE, EMBASE, and CINAHL for HF RCTs published in journals with an impact factor ≥10 between January 1, 2000, and June 17, 2020. We used the Jonckheere-Terpstra test to assess temporal trends and multivariable logistic regression models to determine associations between predictor and outcome variables.

There were 414 eligible RCTs. Only 80 of 828 trial leaders (9.7%; 95% CI: 7.8% to 11.8%), and 453 of 4656 collaborators (9.7%; 95% CI: 8.8% to 10.6%) were from regions outside Europe and North America, with no temporal change in geographic representation. The odds of trial leadership outside Europe and North America were significantly lower with industry versus public funding (OR: 0.33; 95% CI: 0.15 to 0.75; P=0.008). Trial leadership outside Europe and North America was associated with enrolment of patients outside Europe and North America (OR: 10.0; 95% CI 5.6–19.0; P<0.001).

Conclusion

Trial leadership outside Europe and North America is rare, particularly in industry funded trials, and is associated with participant enrolment in regions with disproportionate disease burden. Building research capacity and networks in under-represented regions could increase generalizability of trial results.

Funding Acknowledgement

Type of funding sources: None.

Meta-analysis of up to 622,409 individuals identifies 40 novel smoking behaviour associated genetic loci

Smoking is a major heritable and modifiable risk factor for many diseases, including cancer, common respiratory disorders and cardiovascular diseases. Fourteen genetic loci have previously been associated with smoking behaviour-related traits. We tested up to 235,116 single nucleotide variants (SNVs) on the exome-array for association with smoking initiation, cigarettes per day, pack-years, and smoking cessation in a fixed effects meta-analysis of up to 61 studies (up to 346,813 participants). In a subset of 112,811 participants, a further one million SNVs were also genotyped and tested for association with the four smoking behaviour traits. SNV-trait associations with P < 5 × 10-8 in either analysis were taken forward for replication in up to 275,596 independent participants from UK Biobank. Lastly, a meta-analysis of the discovery and replication studies was performed. Sixteen SNVs were associated with at least one of the smoking behaviour traits (P < 5 × 10-8) in the discovery samples. Ten novel SNVs, including rs12616219 near TMEM182, were followed-up and five of them (rs462779 in REV3L, rs12780116 in CNNM2, rs1190736 in GPR101, rs11539157 in PJA1, and rs12616219 near TMEM182) replicated at a Bonferroni significance threshold (P < 4.5 × 10-3) with consistent direction of effect. A further 35 SNVs were associated with smoking behaviour traits in the discovery plus replication meta-analysis (up to 622,409 participants) including a rare SNV, rs150493199, in CCDC141 and two low-frequency SNVs in CEP350 and HDGFRP2. Functional follow-up implied that decreased expression of REV3L may lower the probability of smoking initiation. The novel loci will facilitate understanding the genetic aetiology of smoking behaviour and may lead to the identification of potential drug targets for smoking prevention and/or cessation.

FRI0423 CLINICAL BURDEN OF TREATING COMMERCIALLY-INSURED OSTEOARTHRITIS PATIENTS WITH PRESCRIPTION NSAIDS

Background:

Prescription NSAIDs/Cox-2s (“NSAIDs”) are commonly prescribed by physicians to treat patients with chronic pain, and much is known about the potential negative outcomes associated with their use1. Such negative outcomes include gastrointestinal (“GI”) issues and hepatorenal toxicity.1In addition, CV risk of Cox-2s has not been completely clarified.1,2However, less is known about the extent to which these outcomes are pervasive and problematic in specific patient populations such as those diagnosed with osteoarthritis (“OA”).

Objectives:

The goal of this research is to assess the clinical burden of commercially-insured patients diagnosed with OA of the hip and/or knee before and after treatment with prescription NSAIDs, in a large, national database in recent years.

Methods:

The Optum Healthcare Solutions, Inc. data (1/2012-3/2017) were used to identify patients ≥18 years old with ≥2 diagnoses of hip and/or knee OA, and ≥90 days supply of NSAIDs during the three-year period from first prescription (index date) after their first OA diagnosis. Patients were required to be continuously-enrolled during the six months before (baseline period) and 36 months after (follow-up period) the index date. Selected clinical outcomes such as GI issues, CV events, and renal toxicity were compared between the baseline and follow-up periods. Costs and resource use were normalized to account for differential duration in analytic time periods.

Results:

Data for 22,435 patients (60.8% as female, with an average age of 62) with hip and/or knee OA were analyzed. On average, patients were prescribed NSAIDs for 489 days during the follow-up period. From the baseline period to follow-up period, negative clinical outcomes associated with GI issues increased by 393% (1.5% v 7.5%), driven by a 667% (0.3% v 2.3%) increase in acute GI hemorrhages. Additionally, negative clinical outcomes associated with CV events increased by 73% (40.7% v 70.6%), largely due to a 600% (0.3% v 2.1%) increase in acute myocardial infarction. Lastly, negative clinical outcomes associated with renal toxicity increased by 433% (1.5% v 8.0%), with a 740% (0.5% v 4.2%) increase in acute renal failure being the most substantial.

Conclusion:

These findings suggest that prescribing of NSAIDs among OA patients is associated with an increase in negative clinical outcomes. This suggests that new treatment options other than NSAIDs should be evaluated.

References:

[1]van Laar M, et al. Pain treatment in arthritis-related pain: beyond NSAIDs.Open Rheumatol J. 2012;6:320–330.

[2]Nissen SE, et al. Cardiovascular safety of celecoxib, naproxen, or ibuprofen for arthritis.NEJM2016;2519-2529.

Disclosure of Interests:

Stuart Silverman Consultant of: Pfizer and Eli Lilly for this project., Speakers bureau: Amgen, Radius, James Rice Consultant of: Pfizer and Eli Lilly have funded this project., Alan White Consultant of: Pfizer and Eli Lilly have funded this project., Nguyen Le Consultant of: Pfizer and Eli Lilly have funded this project., Michael Somma Consultant of: Eli Lilly and Pfizer have funded this project., Craig Beck Shareholder of: Pfizer, Employee of: Pfizer, Rebecca Robinson Shareholder of: Eli Lilly, Employee of: Eli Lilly, Patricia Schepman Shareholder of: Pfizer, Employee of: Pfizer

Exome Chip Meta-analysis Fine Maps Causal Variants and Elucidates the Genetic Architecture of Rare Coding Variants in Smoking and Alcohol Use

BACKGROUND

Smoking and alcohol use have been associated with common genetic variants in multiple loci. Rare variants within these loci hold promise in the identification of biological mechanisms in substance use. Exome arrays and genotype imputation can now efficiently genotype rare nonsynonymous and loss of function variants. Such variants are expected to have deleterious functional consequences and to contribute to disease risk.

METHODS

We analyzed ∼250,000 rare variants from 16 independent studies genotyped with exome arrays and augmented this dataset with imputed data from the UK Biobank. Associations were tested for five phenotypes: cigarettes per day, pack-years, smoking initiation, age of smoking initiation, and alcoholic drinks per week. We conducted stratified heritability analyses, single-variant tests, and gene-based burden tests of nonsynonymous/loss-of-function coding variants. We performed a novel fine-mapping analysis to winnow the number of putative causal variants within associated loci.

RESULTS

Meta-analytic sample sizes ranged from 152,348 to 433,216, depending on the phenotype. Rare coding variation explained 1.1% to 2.2% of phenotypic variance, reflecting 11% to 18% of the total single nucleotide polymorphism heritability of these phenotypes. We identified 171 genome-wide associated loci across all phenotypes. Fine mapping identified putative causal variants with double base-pair resolution at 24 of these loci, and between three and 10 variants for 65 loci. Twenty loci contained rare coding variants in the 95% credible intervals.

CONCLUSIONS

Rare coding variation significantly contributes to the heritability of smoking and alcohol use. Fine-mapping genome-wide association study loci identifies specific variants contributing to the biological etiology of substance use behavior.

Time Trend of Liver Cancer Among Subpopulation of Ages Less Than 40 During 2005-2014 in Nghe An, Viet Nam

Background: Liver cancer has been leading cancer mortality nationwide in Viet Nam. Aim: The aim was to examine time trends of liver cancer mortality by performing population-based mortality registration in Nghe An province, 2005-2014. Methods: We yearly collected data from all 480 Commune Health Stations from 2005 to 2014 using the designed form of “Mortality Registration” with a guideline of underlying-, immediate, - and contribute cause of death. Five variables were included name, age, sex, date of death and cause of death. Average residents of each commune were also yearly reported. All cases were coded ICD-10, then liver cancer (C22) was derived. Age-standardized rate (ASR) was estimated. Trend of liver cancer was observed by estimated mortality rates ratio and 95% confident interval (MRR) for 5-period of 2005-2006 (reference), 2007-2008, 2009-2010, 2011-2012, 2013-2014, adjusted for total mortality rate and proportion of cases with unknown causes of death, for total, subgroup of ages 40 or older, and ages less than 40. Results: Among registered 7,667 cases of liver cancer, there were 855 cases aged less than 40. Mortality rates per 100,000 (ASR) were increased from 37.4 to 52.8 in men and 9.2 to 12.6 in women, from 2005 to 2014, respectively. The increased trends were significantly seen for the subpopulation ages 40 or older only, MRR=1.56, 95% CI: 1.38-1.76 in men and MRR=1.67, 95% CI: 1.36-2.04 in women, all P trend < 0.05. In contrast, the decreased trends were significantly observed for the subpopulation ages less than 40, MRR=0.72, 95% CI: 0.54-0.97 in men and MRR=0.47, 95% CI: 0.22-0.99 in women, all P trend < 0.05. Conclusion: The significant decline risks of death from liver cancer for the subpopulation ages less than 40 during 2005-2014 might be explained by HBV vaccine nationwide from 1998 to date and reduction of environmental factors induced this cancer sites in improving healthy environments after the war ended in 1975. Key-words: Liver-cancer, population-based mortality registration, Viet Nam, HBV-vaccine.

Current Achievement and Challenges of Food, Cooking Methods and Cancer Control: A Pooled Multivariable-Adjusted Analysis for the Association Between Meat Mutagens Intake and Colorectal Adenoma and Cancer

Background: Heterocyclic amines (HCAs), a group of dietary carcinogens, have been hypothesized to increase risk of colorectal adenoma (CRA) cancer (CRC). However, previous findings have been inconsistences. Aim: The aim was to pool analysis of multivariable-adjusted relative risks from published articles for the association between HCAs intake and the risk of CRD and CRC. Methods: We used all available 34 published articles to access the multivariable-adjusted relative risk (hazard ratio or odds ratio) and their 95% confidence interval (95% CI) to estimate ln(RR) and se(ln(RR)). The HCAs 2-amino-3,8-dimethylimidazo[4,5,-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,4,8-trimethylimidazo[4,5,-f]quinoxaline (DiMeIQx), and meat-derived mutagenicity (MDM) were examined. The random pooled RR, 95% CI was analyzed in using ln(RR) and se(ln(RR)) for separated prospective cohort studies and case-control studies by STATA-10. Results: Prospective cohort studies have examined for 5,684 CRC occurred among 528,111 registered participants; and for 2,484 CRA occurred among 136,902 registered participants. Case-control studies have examined for 12,753 CRC and 17,152 matched controls; and for 10,821 CRA and 45,099 matched controls. PhIP was majority contributed by cooked chicken (54%–74%). MeIQx was mainly contributed by red meat (83%–92%). For prospective cohort studies on CRC, fifth versus first-quintile, the random pooled RR, (95% CI) was 1.11, (1.00, 1.23), P = 0.052 for MDM; 1.00, (0.91, 1.09), P = 0.958 for PhIP; 1.12, (1.03, 1.22), P = 0.009 for MeIQx; 1.03, (0.87, 1.22), P = 0.763 for DiMeIQx. For CRA, third versus first-quintile, the random pooled RR, (95% CI) was 1.13, (0.92, 1.39), P = 0.237 for MDM; 1.11, (0.96, 1.29), P = 0.169 for PhIP; 1.14, (1.00, 1.30), P = 0.048 for MeIQx; 1.00, (0.87, 1.15), P = 0.999 for DiMeIQx. For case-control studies, the null association was observed for PhIP, DiMeIQx and CRC. A positive association was significantly seen for MeIQx, MDM and both CRC and CRA. Conclusion: Because intake of MeIQx significantly increased the risk of both CRC and CRA in both prospective cohort and case-control studies, the findings support to the hypothesis of the role of underlying mechanisms of red meat induced CRC.

Association of substance dependence phenotypes in the COGA sample

Alcohol and drug use disorders are individually heritable (50%). Twin studies indicate that alcohol and substance use disorders share common genetic influences, and therefore may represent a more heritable form of addiction and thus be more powerful for genetic studies. This study utilized data from 2322 subjects from 118 European-American families in the Collaborative Study on the Genetics of Alcoholism sample to conduct genome-wide association analysis of a binary and a continuous index of general substance dependence liability. The binary phenotype (ANYDEP) was based on meeting lifetime criteria for any DSM-IV dependence on alcohol, cannabis, cocaine or opioids. The quantitative trait (QUANTDEP) was constructed from factor analysis based on endorsement across the seven DSM-IV criteria for each of the four substances. Heritability was estimated to be 54% for ANYDEP and 86% for QUANTDEP. One single-nucleotide polymorphism (SNP), rs2952621 in the uncharacterized gene LOC151121 on chromosome 2, was associated with ANYDEP (P = 1.8 × 10(-8) ), with support from surrounding imputed SNPs and replication in an independent sample [Study of Addiction: Genetics and Environment (SAGE); P = 0.02]. One SNP, rs2567261 in ARHGAP28 (Rho GTPase-activating protein 28), was associated with QUANTDEP (P = 3.8 × 10(-8) ), and supported by imputed SNPs in the region, but did not replicate in an independent sample (SAGE; P = 0.29). The results of this study provide evidence that there are common variants that contribute to the risk for a general liability to substance dependence.

Genome-wide survival analysis of age at onset of alcohol dependence in extended high-risk COGA families

BACKGROUND

The age at onset of alcohol dependence (AD) is a critical moderator of genetic associations for alcohol dependence. The present study evaluated whether single nucleotide polymorphisms (SNPs) can influence the age at onset of AD in large high-risk families from the Collaborative Study on the Genetics of Alcoholism (COGA).

METHODS

Genomewide SNP genotyping was performed in 1788 regular drinkers from 118 large European American families densely affected with alcoholism. We used a genome-wide Cox proportional hazards regression model to test for association between age at onset of AD and SNPs.

RESULTS

This family-based analysis identified an intergenic SNP, rs2168784 on chromosome 3 that showed strong evidence of association (P=5×10(-9)) with age at onset of AD among regular drinkers. Carriers of the minor allele of rs2168784 had 1.5 times the hazard of AD onset as compared with those homozygous for the major allele. By the age of 20 years, nearly 30% of subjects homozygous for the minor allele were alcohol dependent while only 19% of those homozygous for the major allele were. We also identified intronic SNPs in the ADP-ribosylation factor like 15 (ARL15) gene on chromosome 5 (P=1.11×10(-8)) and the UTP20 small subunit (UTP20) gene on chromosome 12 (P=4.32×10(-8)) that were associated with age at onset of AD.

CONCLUSIONS

This extended family based genome-wide cox-proportional hazards analysis identified several loci that might be associated with age at onset of AD.

Family-based association analysis of alcohol dependence criteria and severity

BACKGROUND

Despite the high heritability of alcohol dependence (AD), the genes found to be associated with it account for only a small proportion of its total variability. The goal of this study was to identify and analyze phenotypes based on homogeneous classes of individuals to increase the power to detect genetic risk factors contributing to the risk of AD.

METHODS

The 7 individual DSM-IV criteria for AD were analyzed using latent class analysis (LCA) to identify classes defined by the pattern of endorsement of the criteria. A genome-wide association study was performed in 118 extended European American families (n = 2,322 individuals) densely affected with AD to identify genes associated with AD, with each of the 7 DSM-IV criteria, and with the probability of belonging to 2 of 3 latent classes.

RESULTS

Heritability for DSM-IV AD was 61% and ranged from 17 to 60% for the other phenotypes. A single nucleotide polymorphism (SNP) in the olfactory receptor OR51L1 was significantly associated (7.3 × 10(-8) ) with the DSM-IV criterion of persistent desire to, or inability to, cut down on drinking. LCA revealed a 3-class model: the "low-risk" class (50%) rarely endorsed any criteria and none met criteria for AD; the "moderate-risk" class (33%) endorsed primarily 4 DSM-IV criteria and 48% met criteria for AD; and the "high-risk" class (17%) manifested high endorsement probabilities for most criteria and nearly all (99%) met criteria for AD. One SNP in a sodium leak channel NALCN demonstrated genome-wide significance with the high-risk class (p = 4.1 × 10(-8) ). Analyses in an independent sample did not replicate these associations.

CONCLUSIONS

We explored the genetic contribution to several phenotypes derived from the DSM-IV AD criteria. The strongest evidence of association was with SNPs in NALCN and OR51L1.

Abstract 2366: Protein tyrosine kinase substrates profiling to detect short-term survivors in early stage lung adenocarcinoma

Introduction: With existing therapeutic efforts, patients with lung cancer have a poor prognosis. Assessment of tumor size, lymph node status and presence of metastases is currently applied for determining prognosis and treatment modality, but predicted and real outcomes can vary significantly. Biomarkers with reliable prognostic significance are therefore of utmost importance but due to a lack of immediate correlation between levels of protein and their corresponding mRNA, a screen based on the kinase activity become a promising option to circumvent this limitation with the tremendeous advantage of focusing on therapeutically targetable enzymatic activities. Several protein tyrosine kinase inhibitors already clinically approved for the treatment of lung cancer are targeting some of the 400 types of DNA signatures described in silico in the human genome. The aim of this study is to clarify the following hypothesis: Is the in vitro multiplexed tyrosine phosphorylation of substrates a possible approach to molecularly classify the kinome of early stage lung adenocarcinoma biopsies and obtain a diagnostic /prognostic signature correlating with the survival of patients?

Methods: We have built a tumor bank of frozen malignant and non-neoplastic lung surgically obtained specimen and recorded all clinical interventions, follow up treatments and outcome for each of our patients. We incubated TNM stage 1 and 2 lung adenocarcinoma kinomes on PamChip®4 microarrays and followed the kinetics of the multiplexed tyrosine phosphorylation for 144 peptides substrates. Image quantification, quality control, statistical analysis and interpretation of data were performed with the BionavigatoR software.

Results: We screened 84 paired malignant TNM stage 1 and 2 lung adenocarcinoma and non-neoplastic lung biopsies for the multiplex tyrosine phosphorylation of substrates immobilized on a PamChip®4microarrays. Based on a 76-point ‘response-signature’ we obtained 73 % of correct prediction with a 10 fold cross validation PLS-DA analysis in TNM stage 1 lung adenocarcinoma biopsies. Moreover, we detected 26 peptides substrates significantly more inhibited in kinomes of long-term survivors than in kinomes of the short-term survivors.

Conclusions: In frozen biopsies of TNM stage I adenocarcinoma and with a PLS-DA analysis applied to a 76-point ‘response-signature’ we present the feasibility to discriminate between long-term and short-term survivors. Furthermore, the found differences in enzymatic activities in lung biopsies may result in the identification of new targets in future anti lung cancer therapy efforts.

Citation Format: Stephan Arni, Nhung Le, Walter Weder, Sven Hillinger, Rik de Wijn, Martjin Dankers. Protein tyrosine kinase substrates profiling to detect short-term survivors in early stage lung adenocarcinoma. [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 2366. doi:10.1158/1538-7445.AM2013-2366

A phase Ib study of the MEK inhibitor GSK1120212 combined with gemcitabine in patients with solid tumors: Interim results

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Background: GSK1120212 (212) is a reversible, allosteric inhibitor of MEK1/MEK2. The objectives of this open-label, single-arm study are to evaluate the safety, pharmacokinetics (PK), and anti-tumor activity of 212 + gemcitabine (gem), and to determine the recommended phase II regimen (RP2R) in patients (pts) with advanced solid tumors.

Methods: 212 (1-2.5mg) is given continuously, orally, once daily. Gem (1,000mg/m2) is infused on days 1, 8, and 15 every 28 days. Doses are escalated to the maximum tolerated dose (MTD) and followed by an expansion cohort to confirm the RP2R tolerability.

Results: 28 pts received ≥ 1 dose of 212 + gem, including 8 pancreatic, 6 breast, and 4 non-small cell lung (NSCLC) cancer pts. The MTD and RP2R is 2mg 212 + 1,000mg/m2 gem. Dose-limiting toxicities (DLTs) are G3/G4 febrile neutropenia (n=2), G3 AST elevation (n=2), and G2 uveitis (n=1). 16 serious adverse events (SAEs) were reported; 5 were considered to be related to study drugs (1 pneumonitis, 3 febrile neutropenia, 1 dyspnea). All DLTs and SAEs have resolved. The most common AEs at the RP2R (n=18) were rash (78%), fatigue (67%), thrombocytopenia (61%), neutropenia (50%), decreased appetite (50%), nausea (44%), diarrhea and constipation (39%); all ≤ G2 except thrombocytopenia (17% ≥ G3) and neutropenia (33% ≥ G3). Co-administration did not affect the PK profiles of 212 or gem. 25 pts had measurable disease at baseline. 1 pancreatic cancer pt with previous radiotherapy and 2 cycles of gem achieved a partial response and stayed on study for 6 months. 3 additional pancreatic cancer pts reported stable disease; 2 of which were on the study for 3.5-5 months and the third pt continues in the study. 1 triple-negative breast cancer pt, refractory to chemotherapy, and 1 parotid cancer pt experienced a complete response of their target lesions.

Conclusions: 212 + gem is tolerable with an acceptable safety profile in this pt population, with evidence of clinical activity in pancreatic cancer. A randomized phase II study in previously untreated patients with metastatic pancreatic cancer is underway to investigate the clinical activity of this combination.

[Table: see text]

Protective Effect of Estrogen (E2) and Increased Risk of E2 Plus Progestin (Prog) on Breast Cancer (BrCa). The 2009 Review of the Women's Health Initiative (WHI) Hormone Replacement Therapy (HRT) Published Trials

INTRODUCTION & METHODOLOGY.The objective of this review is to identify from the two WHI published randomized HRT trials the BrCa risk or benefit, with a special focus on different impact of E2-alone vs E2+Prog on human breast carcinogenesis (BrCa-genesis).In the 1st trial (JAMA 2002, 2007), healthy women age 50 - 79 were randomized to E2 plus Prog versus placebo (Plac). Reviewed were Hazard ratios (HRs) for all pts and also for those with or without prior Hormone use. Mean follow up was 5.2 years.In the 2nd trial (JAMA 2004, 2006), women with hysterectomy age 50 - 79 were randomized to E2 alone (without Prog) versus Plac. Mean follow up was 7.1 years. Reviewed were all pts, and also subsets with or without prior E2 or Prog; with or without prior history of Benign Breast Disease (PHBrD); and with or without prior history of a 1st degree relative with BrCa (PH1stRelBrCa).RESULTS.Invasive BrCa incidence:N (%)HR95% C.I.1st TrialAll participants:16,608 (100%)1.260.83 - 1.97No prior Hormone use:12,304 (74.1%)1.060.81 - 1.38Prior Hormone use &lt;5 yrs:3,005 (18.1%)2.131.15 - 3.94*Prior Hormone use 5 - 10 yrs:783 (4.7%)4.611.01 - 21.02*2nd TrialAll participants:10,739 (100%)0.800.62 - 1.04No prior hormone use:5,763 (53.7%)0.650.46 - 0.92*Prior E2 use:4,976 (46.3%)0.980.67 - 1.44Prior E2 + PROG use:468 (4.4%)2.350.60 - 9.14No PHBrD:7,681 (71.5%)0.570.41 - 0.78*No PH1stRelBrCa8,554 (80.0%)0.680.50 - 0.92*CONCLUSION:1. Results from the 1st trial show that concomitant use of E2 with Prog, particularly in women with prior Hormone use, is associated with increased BrCa hazards.2. The results of the 2nd HRT trial indicate that use of HRT with E2 alone is associated with a reduction in BrCa incidence, significant in the majority of women with no prior BrCa risk factors. Also the results show that prior Prog but not prior E2 elevate the risk.3. These data indicate that HRT with E2 alone has a BrCa protective effect, while adding Prog increases the risk.4. These results are also compatible with a dual E2 effect on BrCa-genesis, where exogenous E2 are protective, but endogenous E2 [endE2] are carcinogenic, as shown from decades of anti-end E2 research with Tamoxifen, oophorectomy or Aromatase inhibitors.5. Based on these data we propose that in women with hysterectomy and no prior history of risk factors, the use of HRT with E2 alone as chemoprevention is plausible, and needs urgent verification.* significance, "p" &lt;0.05.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 908.

Preoperative tumor markers at diagnosis in women with malignant mixed müllerian tumors/carcinosarcoma of the uterus

CA125 is a well-recognized marker for endometrial cancer. Uterine malignant mixed müllerian tumors (MMMTs) are increasingly being recognized as an aggressive adenocarcinoma, not a sarcoma. There are no data in the literature regarding CA125 in this malignancy. One hundred twelve women with surgically staged MMMT, diagnosed between July 1990 and September 2005, had a retrospective chart review performed. Preoperative CA125 levels were available in 29 (26%) women. Seventeen (49%) women had levels above the upper limit of normal of 35 kμ/L. Mean levels increased with increasing surgical stage: stage I 53.4 kμ/L; stage II 122.5 kμ/L; stage III 147.1 kμ/L; and stage IV 428.4 kμ/L. Elevated levels of CA19-9, CEA, and CA15-3 were found in 8%, 12%, and 25%, respectively.

Myocardial protection by isoflurane vs. sevoflurane in ultra-fast-track anaesthesia for off-pump aortocoronary bypass grafting

BACKGROUND AND OBJECTIVES

Volatile anaesthetics have gained more popularity recently due to the potential for cardiac protection. Ultra-fast-track anaesthesia implies the immediate extubation after cardiac surgery. The purpose of this prospective randomized double-blind controlled study is to compare the cardioprotective effects of sevoflurane and isoflurane in off-pump cardiac bypass surgery.

METHODS

Forty patients undergoing elective off-pump cardiac bypass surgery with high thoracic epidural analgesia and immediate extubation at the end of surgery were randomized into two groups. During surgery, anaesthesia was provided with either 1 minimum alvelolar anaesthetic concentration of sevoflurane or 1 minimum alvelolar anaesthetic concentration of isoflurane. Troponin-T, creatine kinase-MB, left ventricular wall motion anomalies, time to extubation, respiratory functions and haemodynamic parameters were compared between the two groups by analysis of variance.

RESULTS

All patients were successfully extubated in the operating theatre with minimal postoperative pain. Serial creatine kinase-MB and troponin-T concentrations were not significantly different between the two volatile agents. Haemodynamic stability throughout surgery and contractility was not different between groups. However, extubation time was significantly shorter with sevoflurane (10 +/- 5 min) compared to isoflurane (18 +/- 4 min).

CONCLUSION

This study indicates that during off-pump cardiac bypass surgery, sevoflurane and isoflurane provide the same ischaemic cardioprotective effects. There is no difference for heart contractility and haemodynamic values during and after off-pump cardiac bypass surgery between the two agents. Sevoflurane allows a more rapid recovery from anaesthesia, but this does not translate into better pulmonary function or haemodynamics. Both agents are similar in ultra-fast-track off-pump cardiac bypass surgery.

Comparison of three different epidural solutions in off-pump cardiac surgery: pilot study

BACKGROUND

Immediate extubation using thoracic epidural analgesia (TEA) has become more popular after off-pump coronary artery bypass grafting (OPCAB). In this randomized prospective double-blind study, we present the first comparison of preoperative and postoperative haemodynamics during different regimens of TEA for immediate extubation after cardiac surgery.

METHODS

Sixty patients undergoing OPCAB were enrolled in this study. TEA was installed >1 h before application of heparin at levels T2-T4. Analgesia was provided by bupivacaine 0.25%, 8 ml, 15 min before surgery and extubation, and at 10 ml h(-1) during surgery and up to 72 h afterwards using one of the following regimens: bupivacaine 0.125% alone, bupivacaine 0.125% with fentanyl 3 microg ml(-1) or bupivacaine 0.125% with clonidine 0.6 microg ml(-1). Patients were block-randomized for one of the three treatments. Pain scores and infusion rates of TEA were assessed up to 48 h after surgery. Respiratory function was assessed by Pa(o2) and Pa(o2) immediately after surgery, and haemodynamic stability was recorded in the form of heart rate and diastolic and systolic blood pressure.

RESULTS

Patient characteristics, respiratory function and haemodynamic stability did not vary between the three groups. Pain control was very good and was not significantly different between the groups using similar infusion rates after surgery. Paraesthesia in dermatomes T1 or C8 occurred equally in all three groups. There was no neurological complication related to TEA in this study.

CONCLUSIONS

We conclude that immediate extubation after OPCAB using TEA is feasible with different TEA regimens. Respiratory function, haemodynamic stability and pain control are not different between TEA with bupivacaine alone, bupivacaine with fentanyl or bupivacaine with clonidine.

Hodgkin’s lymphoma in Chinese migrants to British Columbia:a 25-year survey

BACKGROUND

Compared with the West, Hodgkin's lymphoma in Oriental countries is characterized by a lower incidence rate and a higher proportion of mixed cellularity histology. Both environmental and genetic factors may be involved.

PATIENTS AND METHODS

The incidence and pattern of pathology of Hodgkin's lymphoma in the migrant Chinese population (0.4 million) in British Columbia (population 3.2 million) were studied. From a computerized database, all Hodgkin's lymphoma cases diagnosed in British Columbia from 1970 to 1997 were identified. Chinese descent was determined using patient surname by standard methodology and verified from the treatment record or by patient interview. The corresponding figures from the Chinese population in Hong Kong were used for comparison. For incidence rates, the age-specific incidence of Hodgkin's lymphoma in Hong Kong was obtained from the government cancer registry. For comparison of histology subtypes, 200 Hodgkin's lymphoma records from a Hong Kong regional referral center for the same time period were reviewed. Crude and age-standardized incidence rates were calculated by 5-year intervals in terms of age and calendar year, and relative rates were compared between the three populations.

RESULTS

From 1970 to 1997, Hodgkin's lymphoma was diagnosed in 34 Chinese patients in BC, with 24 cases diagnosed from 1970 to 1994. Thus, the crude and age-adjusted incidence rates from 1970 to 1994 were 0.91 and 1.14 per 100,000 per year in the British Columbia Chinese migrant population. Within the same period, 1862 cases of Hodgkin's lymphoma were diagnosed in British Columbia, giving a provincial background crude and age-adjusted incidence rates of 5.2 and 4.87 per 100,000 per year. The number of cases in the Hong Kong Chinese population (1970-1994) was 404, giving crude and age-adjusted incidence rates of 0.32 and 0.31 per 100,000 per year, respectively. Corrected for age and calendar year trends, the observed 25-year incidence of Hodgkin's lymphoma in British Columbia Chinese was significantly lower than expected from the British Columbia background population [24 observed versus 71 expected cases; standardized incidence ratio (SIR) = 0.34; 90% confidence interval (CI) 0.24-0.48; P <0.0001]. On the other hand, it is higher than that expected by extrapolating from the Hong Kong Chinese population (24 observed versus 8.5 expected cases; SIR = 2.81; 90% CI 1.94-3.95; P <0.0001). The difference is mainly accounted for by young patients with nodular sclerosis type disease in the migrant population.

CONCLUSIONS

Although any conclusion about the impact of migration on Hodgkin's lymphoma incidence and types in the Chinese population must be considered tentative due to the small number of observed cases and confounding variables such as age, changing diagnostic standards and secular trends in Hodgkin's lymphoma rates, our data demonstrate a tendency for the Chinese population of British Columbia to take on a Western pattern of Hodgkin's lymphoma. This observation provides additional evidence that both genetic and environmental influences play a role in the pathogenesis of this lymphoma, and that environmental factors can exert their influence over a relatively short period of time.

Rapamycin causes down-regulation of CCR5 and accumulation of anti-HIV beta-chemokines: an approach to suppress R5 strains of HIV-1

Propagation of R5 strains of HIV-1 on CD4 lymphocytes and macrophages requires expression of the CCR5 coreceptor on the cell surface. Individuals lacking CCR5 (CCR5 Delta 32 homozygous genotype) are phenotypically normal and resistant to infection with HIV-1. CCR5 expression on lymphocytes depends on signaling through the IL-2 receptor. By FACS analysis we demonstrate that rapamycin (RAPA), a drug that disrupts IL-2 receptor signaling, reduces CCR5 surface expression on T cells at concentrations as low as 1 nM. In addition, lower concentrations of RAPA (0.01 nM) were sufficient to reduce CCR5 surface expression on maturing monocytes. PCR analysis on peripheral blood mononuclear cells (PBMCs) showed that RAPA interfered with CCR5 expression at the transcriptional level. Reduced expression of CCR5 on PBMCs cultured in the presence of RAPA was associated with increased extracellular levels of macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta. In infectivity assays, RAPA suppressed the replication of R5 strains of HIV-1 both in PBMC and macrophage cultures. In total PBMC cultures, RAPA-mediated inhibition of CCR5-using strains of HIV-1 occurred at 0.01 nM, a concentration of drug that is approximately 103 times lower than therapeutic through levels of drug in renal transplant recipients. In addition, RAPA enhanced the antiviral activity of the CCR5 antagonist TAK-779. These results suggest that low concentrations of RAPA may have a role in both the treatment and prevention of HIV-1 infection.

The HIV protease inhibitor indinavir decreases insulin- and contraction-stimulated glucose transport in skeletal muscle

In many patients with human immunodeficiency virus (HIV) treated with HIV protease inhibitors, a complication develops that resembles abdominal obesity syndrome, with insulin resistance and glucose intolerance that, in some cases, progresses to diabetes. In this study, we tested the hypothesis that indinavir, an HIV-protease inhibitor, directly induces insulin resistance of glucose transport in skeletal muscle. Rat epitrochlearis muscles were incubated with a maximally effective insulin concentration (12 nmol/l) and 0, 1, 5, 20, or 40 micromol/l indinavir for 4 h. In control muscles, insulin increased 3-O-[(3)H]methyl-D-glucose (3MG) transport from 0.15 +/- 0.03 to 1.10 +/- 0.05 micromol. ml(-)(1). 10 min(-)(1). Incubation of muscles with 5 micromol/l indinavir reduced the insulin-stimulated increase in 3MG transport by 40%, whereas 20 micromol/l indinavir reduced the insulin-stimulated increase in 3MG transport by 58%. Indinavir induced a similar reduction in maximally insulin-stimulated 3MG transport in the soleus muscle. The increase in glucose transport activity induced by stimulating epitrochlearis muscles to contract was also markedly reduced by indinavir. The insulin-stimulated increase in cell-surface GLUT4, assessed using the 2-N-4-(1-azi-2,2,2-trifluoroethyl)benzoyl-1,3-bis-[2-(3)H] (D-mannose-4-yloxy)-2-propylamine exofacial photolabeling technique, was reduced by approximately 70% in the presence of 20 micromol/l indinavir. Insulin stimulation of phosphatidylinositol 3-kinase activity and phosphorylation of protein kinase B were not decreased by indinavir. These results provide evidence that indinavir inhibits the translocation or intrinsic activity of GLUT4 rather than insulin signaling.

EGR2 mutations in inherited neuropathies dominant-negatively inhibit myelin gene expression

The identification of EGR2 mutations in patients with neuropathies and the phenotype Egr2/Krox20(-/-) have demonstrated that the Egr2 transcription factor is critical for peripheral nerve myelination. However, the mechanism by which these mutations cause disease remains unclear, as most patients present with disease in the heterozygous state, whereas Egr2(+/-) mice are phenotypically normal. To understand the effect of aberrant Egr2 activity on Schwann cell gene expression, we performed microarray expression profiling to identify genes regulated by Egr2 in Schwann cells. These include genes encoding myelin proteins and enzymes required for synthesis of normal myelin lipids. Using these newly identified targets, we have shown that neuropathy-associated EGR2 mutants dominant-negatively inhibit wild-type Egr2-mediated expression of essential myelin genes to levels sufficiently low to result in the abnormal myelination observed in these patients.

Differential human immunodeficiency virus-suppressive activity of reverse transcription inhibitors in resting and activated peripheral blood lymphocytes: implications for therapy

OBJECTIVES

Because recent evidence indicates that human immunodeficiency virus type 1 (HIV-1) propagates in resting T lymphocytes in vivo, we wanted to evaluate the antiviral effects exerted by currently used nucleoside (NRTI) and non-nucleoside analog reverse transcription inhibitors in resting lymphocytes, and compare those effects to the ones obtained in activated lymphocytes.

METHODS

Tissue culture antiviral assays in which target cells are lymphocytes present in a resting or activated state. Virus replication was measured by a reverse transcription (RT) assay. Cell viability was evaluated using a commercial 3-(4k5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

RESULTS

In vitro results obtained with concentrations of zidovudine and stavudine equivalent to drug levels found in plasma, showed more than 99% HIV-1 inhibition in activated lymphocytes but less than 50% virus inhibition in resting lymphocytes. Conversely, plasma levels of didanosine-inhibited HIV-1 by approximately 50% and 98% in activated and resting lymphocytes, respectively. Plasma level concentration of zalcitabine, lamivudine, and abacavir inhibited viral replication by more than 90% in both resting and activated cells.

CONCLUSIONS

These data demonstrate that specific NRTI antiretroviral agents have different activity against HIV RT, depending on the state of cell cycle of the infected cell. We suggest that the replication of HIV-1 in resting lymphocytes should be taken into account in the design of future clinical trials, as well as treatment antiretroviral regimens. Selection of combination RTIs so that they provide antiretroviral activity in both resting and activated lymphocytes may be a way to minimize treatment failure and the emergence of drug-resistant variants.

The correlation between epidermal growth factor levels in saliva and the severity of oral mucositis during oropharyngeal radiation therapy

BACKGROUND

Epidermal growth factor (EGF) is present in biologic fluids, including saliva, and plays a role in maintenance of the epithelial barrier and in healing of damaged mucosa. The purpose of this study was to assess the relation between salivary EGF and the severity of oral mucositis in patients with carcinoma of the head and neck during radiation therapy.

METHODS

Whole resting saliva (WRS) and whole stimulated saliva (WSS) were collected prior to radiation and each week during radiation treatment for 11 men and 7 women. Oral mucositis was evaluated using the National Cancer Institute (NCI) scale of 0-4 and the Oral Mucositis Assessment Scale (OMAS), which evaluates the extent of erythema (scale of 0-2) and ulcerations (scale of 0-3) in nine oral sites. The overall OMAS score of 0-45 reflected the mucosal condition. EGF was assayed in the saliva specimens.

RESULTS

The total mean radiation dose delivered to the head and neck was 5667 centigrays (cGy) in a mean of 24 fractions. Ulcerative oral mucositis occurred in 94% of patients. The mean OMAS score ranged from 2.83 in the first week of treatment to 14.77 in the fifth week. The mean WRS and WSS volumes decreased significantly from pretreatment to the first week of radiation treatment and then remained stable. A similar pattern was seen for the mean total output of EGF. A significant and negative correlation was found between higher levels of EGF in stimulated saliva and low OMAS score, reflecting less severe erythema and ulceration. A general trend showing that less tissue damage was associated with a higher EGF level in resting saliva also was illustrated. EGF levels were correlated with the OMAS score; however, no correlation was found when assessing the NCI score, which combines tissue damage with function and symptoms in a single score.

CONCLUSIONS

Radiation-induced mucositis appeared to be modified by saliva volume, total EGF, and concentration of EGF in the oral environment. Saliva volume and total EGF output decreased significantly in the first weeks of treatment and remained reduced throughout radiation therapy. The findings suggest that higher levels of EGF in saliva, particularly in stimulated saliva, prior to and during radiation treatment may be associated with less severe mucosal damage due to radiation therapy. It is also postulated that human EGF may affect the development and healing of radiation-damaged mucosa.

Primary structure of Noetia ponderosa hemoglobins: functional correlates

Homo- and heterodimeric hemoglobins have been isolated from the red cells of the arcid clam Noetia ponderosa (Np). These hemoglobins bind oxygen cooperatively. An extensively studied dimeric hemoglobin from another arcid clam, Scapaharca inaequivalvis, exhibits a molecular mechanism for cooperative ligand binding that is radically different from tetrameric vertebrate hemoglobins. In this study, the two chains found in both Noetia hemoglobins are sequenced and compared to the hemoglobins of the related clam S. inaequivalvis to determine whether Noetia hemoglobins have the structural basis for the same unusual mechanism for cooperative ligand binding and to inquire about the structural basis of absence of tetramers. Although the Noetia sequences are homologous to the Scapharca sequences, critical differences exist. The lack of tetramerization of Np subunits is most likely related to the absence of critical residues in the A and G helices that stabilize the interdimer contact seen in the Scapharca Hb tetramer. The lower affinity of the homodimer (Np-I), but particularly the heterodimer (Np-II) with respect to the homodimer and heterotetramer of Scapharca, can be due to (i) changes in the proximal heme environment and (ii) changes in the dimer interface. Interactions between Asn 100 and the heme of the other subunit are altered in Np-II due to the substitution of this residue by methionine, possibly causing the reduced O(2) affinity of the heterodimer of Noetia. (iii) Sequence changes in the E and F helices present in Np-I and Np-II could also contribute to the effect through interfacial changes. In particular, the substitution of Val for Thr in position 72 is expected to have a substantial influence on the interface. We conclude that Np dimers have the structural basis for a direct heme-heme interaction mechanism for cooperativity, as in Scapharca, but there are enough sequence changes to suggest that the pathway of interaction might be somewhat different.

DNA cleavage by 111In-labeled oligodeoxyribonucleotides

We studied the fine structure of DNA damage produced by the decay of 111In incorporated into duplex and triplex DNA strands to evaluate the usefulness of this radionuclide for sequence-specific DNA cleavage.

METHODS

Oligodeoxyribonucleotides (ODNs) were prepared with 111In attached by diethylenetriaminepentaacetic acid (DTPA) at the 5' end or 3' end through a long chemical linker or to an internal nucleotide position through a short linker. Subsequent formation of DNA duplexes and triplexes was confirmed by gel electrophoresis. The 111In-induced breaks were assayed in denaturing polyacrylamide gel electrophoresis with a single-nucleotide resolution.

RESULTS

111In-labeled oligonucleotides of high specific activity (740-1554 TBq/mmol) were synthesized. The presence of the bulky 111In-DTPA group did not impede duplex or triplex formation. Localized DNA breaks were observed in all duplexes and triplexes formed. The majority of DNA breaks in duplex formations were located within +/- 10 nucleotides from the site of attachment of the 111In-bearing linker. The yield of DNA breaks per decay was 0.38 in a duplex with internally modified ODNs. This is nearly 2 times less than the yield of DNA breaks in the same duplex with 1251 attached through the same linker. The yield of DNA breaks in the pyrimidine and purine strands of DNA triplexes with 111In attached to the triplex-forming ODNs through the linkers of different length varied from 0.05 to 0.10. The distribution of DNA breaks was wider in comparison with the duplex experiment. The lower yields of breaks per 111In decay compared with 125I may be not only the result of lower deposited energy but also of the ionic repulsion of the negatively charged 111In-DTPA group from the DNA strands.

CONCLUSION

We have shown that decay of 111In produces highly localized DNA breaks. 111In introduced into triplex- and duplex-forming ODNs through hydrocarbon linkers produces sequence-specific DNA strand breaks with an efficiency nearly comparable with that of 1251. These findings are supportive of our proposed use of 111In-ODNs for gene-specific radiotherapy.

Pharmacokinetics of 111In- and 125I-labeled antiTac single-chain Fv recombinant immunotoxin

The use of immunotoxins for cancer therapy is an attractive strategy that exploits the targeting specificity of monoclonal antibodies and their fragments as well as the exquisite toxicity of the toxins. However, few studies of immunotoxins have evaluated their biodistribution in vivo. Previous studies have used 125I for tracing immunotoxin biodistribution in mice. Because the immunotoxin works only when it is internalized and because of known problems with quick dehalogenation after internalization of antibodies, we decided to use 111In, which has greater intracellular retention than iodine.

METHODS

To trace the in vivo pharmacokinetics of the immunotoxin in mice, we labeled the antiTac(Fv)-PE38 with 111ln and compared it with 125I-labeled antiTac(Fv)-PE38. We successfully labeled antiTac(Fv)-PE38 with 111In at up to 2.96 GBq/mg. A 3- to 4-fold decrease in cytotoxicity was observed for both radiolabeled preparations. We evaluated the internalization of 111In- and 125I-labeled antiTac(Fv)PE38 into ATAC4 cells (Tac-positive) as well as their biodistribution and pharmacokinetics in vivo in mice. In addition, some mice receiving these reagents were co-infused with 30 mg L-lysine to inhibit renal accumulation.

RESULTS

Significantly more 111In- than 125I-labeled antiTac(Fv)-PE38 accumulated in the ATAC4 cells (20% versus 5% of initial surface-bound radioactivity; P < 0.001). In vivo, significantly more 111In- than 125I-labeled antiTac(Fv)-PE38 accumulated in the kidney (119 versus 31 percentage injected dose per gram [%ID/g]; P < 0.001). The tumor accumulation of 111In-labeled antiTac(Fv)-PE38 at 96 h was 13-fold greater than that of 125I-labeled antiTac(Fv)-PE38 (1.4 versus 0.1 %ID/g; P < 0.001). No antiTac(Fv)-PE38 was excreted into the urine in its intact form unless lysine was co-infused. Co-injected lysine reduced the renal accumulation of 111In-labeled antiTac(Fv)-PE38 by 62%.

CONCLUSION

We evaluated the biodistribution, pharmacokinetics, and catabolism of 111In-labeled antiTac(Fv)-PE38 and found that it differed from 125I-labeled antiTac(Fv)PE38. These studies suggest that 111In-labeled antiTac(Fv)-PE38 can be used to trace the fate of antiTac(Fv)-PE38 in humans.