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1.  The quest for effective pain control during suture adjustment after strabismus surgery: a study evaluating supplementation of 2% lidocaine with 0.4% ropivacaine 
Journal of Pain Research  2015;8:33-37.
To determine whether the addition of 0.4% ropivacaine to the standard 2% lidocaine peribulbar anesthetic block improves pain scores during suture adjustment in patients undergoing strabismus surgery with adjustable sutures.
Prospective, double-blind study of 30 adult patients aged 21–84 years scheduled for elective strabismus surgery with adjustable sutures. Patients were divided into two groups of 15 patients each based on the local anesthetic. Group A received 2% lidocaine and Group B received 2% lidocaine/0.4% ropivacaine. Pain was assessed using the visual analog scale (VAS) preoperatively and at 2, 4, and 6 hours postoperatively. The Lancaster red-green test was used to measure ocular motility at the same time points.
The pain scores in the two groups were low and similar at all measurement intervals. The VAS for Group A versus Group B at 2 hours (1.7 versus 2.4, P=0.5) and 4 hours (3.5 versus 3.7, P=0.8) showed no benefit from the addition of ropivacaine. At 6 hours, the VAS (3.7 versus 2.7) was not statistically significant, but the 95% confidence interval indicated that ropivacaine may provide some benefit. A repeated measures ANOVA did not find a statistically significant difference in VAS scores over time (P=0.9). In addition, the duration of akinesia was comparable in both groups (P=0.7).
We conclude that the 50:50 mixture of 2% lidocaine with 0.4% ropivacaine as compared to 2% lidocaine in peribulbar anesthetic blocks in adjustable-suture strabismus surgery does not produce significant improvements in pain control during the postoperative and adjustment phases. In addition, ropivacaine did not impair return of full ocular motility at 6 hours, which is advantageous in adjustable-suture strabismus surgery.
PMCID: PMC4298306  PMID: 25609996
adjustable-suture strabismus surgery; postoperative ocular motility; local anesthetic block; postoperative pain
2.  Metformin Use and Endometrial Cancer Survival 
Gynecologic oncology  2013;132(1):236-240.
Impaired glucose tolerance and diabetes are risk factors for the development of uterine cancer. Although greater progression free survival among diabetic patients with ovarian and breast cancer using metformin have been reported, no studies have assessed the association of metformin use with survival in women with endometrial cancer (EC).
We conducted a single-institution retrospective cohort study of all patients treated for uterine cancer from January 1999 through December 2009. Demographic, medical, social, and survival data were abstracted from medical records and the national death registry. Overall survival (OS) was estimated using Kaplan-Meier methods. Cox models were utilized for multivariate analysis. All statistical tests were two-sided.
Of 985 patients, 114 (12%) had diabetes and were treated with metformin, 136 (14%) were diabetic but did not use metformin, and 735 (74%) had not been diagnosed with diabetes. Greater OS was observed in diabetics with non-endometrioid EC who used metformin than in diabetic cases not using metformin and non-endometrioid EC cases without diabetes (log rank test (p=0.02)). This association remained significant (hazard ratio = 0.54, 95% CI: 0.30–0.97, p<0.04) after adjusting for age, clinical stage, grade, chemotherapy treatment, radiation treatment and presence of hyperlipidemia in multivariate analysis. No association between metformin use and OS in diabetics with endometrioid histology was observed.
Diabetic EC patients with non-endometrioid tumors who used metformin had lower risk of death than women with EC who did not use metformin. These data suggest that metformin might be useful as adjuvant therapy for non-endometrioid EC.
PMCID: PMC3904540  PMID: 24189334
Metformin; endometrial cancer; non-endometrioid; adjuvant therapy; retrospective cohort study
3.  Abnormal Pap tests and human papillomavirus infections among HIV infected and uninfected women who have sex with women 
To estimate the frequency of abnormal Pap and human papillomavirus (HPV) positivity among HIV seropositive and seronegative women who have sex with women (WSW).
Pap and HPV DNA PCR tests were obtained every six months from women in a U.S. cohort of HIV seropositive and seronegative women. WSW were women reporting no male and at least one female sex partner over five years. WSW were frequency matched 1:5 to women reporting sex only with men (WSM) and assessed using multivariable generalized estimating equation logistic regression models.
Paps at study entry were abnormal in 12 (21%) of 49 HIV seropositive WSW, 151 (64%) of 245 HIV seropositive WSM, 3 (9%) of 24 HIV seronegative WSW, and 16 (11%) of 120 seronegative WSM. HPV was found at entry in 18 (42%) HIV seropositive WSW, 109 (52%) HIV seropositive WSM, 6 (27%) HIV seronegative WSW and 13 (13%) HIV seronegative WSM. After controlling for HIV serostatus and CD4 count, WSW had marginally lower odds than WSM of Pap abnormality (O.R. 0.59, 95% C.I. 0.33, 1.03) and of HPV (O.R. 0.53, 95% C.I. 0.32, 0.89). After controlling for partner gender, HIV seropositivity and lower CD4 count were associated with any HPV, oncogenic HPV, any abnormal Pap result, and HSIL or worse (P < 0.0001 for all).
While risks for abnormal Pap and HPV are modestly lower in WSW than WSM, both are common in HIV seropositive women regardless of sexual preference. WSW and WSM should be screened similarly.
PMCID: PMC3905442  PMID: 23959300
Human papillomavirus; HIV in women; women who have sex with women
4.  Personal history of diabetes, genetic susceptibility to diabetes, and risk of brain glioma: a pooled analysis of observational studies 
Brain glioma is a relatively rare and fatal malignancy in adulthood with few known risk factors. Some observational studies have reported inverse associations between diabetes and subsequent glioma risk, but possible mechanisms are unclear.
We conducted a pooled analysis of original data from five nested case-control studies and two case-control studies from the U.S. and China that included 962 glioma cases and 2,195 controls. We examined self-reported diabetes history in relation to glioma risk, as well as effect modification by seven glioma risk-associated single-nucleotide polymorphisms (SNPs). We also examined the associations between 13 diabetes risk-associated SNPs, identified from genome-wide association studies, and glioma risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable-adjusted logistic regression models.
We observed a 42% reduced risk of glioma for individuals with a history of diabetes (OR=0.58, 95% CI: 0.40–0.84). The association did not differ by sex, study design, or after restricting to glioblastoma, the most common histological sub-type. We did not observe any significant per-allele trends among the 13 diabetes-related SNPs examined in relation to glioma risk.
These results support an inverse association between diabetes history and glioma risk. The role of genetic susceptibility to diabetes cannot be excluded, and should be pursued in future studies together with other factors that might be responsible for the diabetes-glioma association.
These data suggest the need for studies that can evaluate, separately, the association between type 1 and type 2 diabetes and subsequent risk of adult glioma.
PMCID: PMC3947107  PMID: 24220915
diabetes mellitus; brain cancer; glioma; cancer; epidemiology
5.  Interquantile Shrinkage and Variable Selection in Quantile Regression 
Examination of multiple conditional quantile functions provides a comprehensive view of the relationship between the response and covariates. In situations where quantile slope coefficients share some common features, estimation efficiency and model interpretability can be improved by utilizing such commonality across quantiles. Furthermore, elimination of irrelevant predictors will also aid in estimation and interpretation. These motivations lead to the development of two penalization methods, which can identify the interquantile commonality and nonzero quantile coefficients simultaneously. The developed methods are based on a fused penalty that encourages sparsity of both quantile coefficients and interquantile slope differences. The oracle properties of the proposed penalization methods are established. Through numerical investigations, it is demonstrated that the proposed methods lead to simpler model structure and higher estimation efficiency than the traditional quantile regression estimation.
PMCID: PMC3956083  PMID: 24653545
Fused adaptive lasso; Fused adaptive sup-norm; Oracle; Quantile regression; Smoothing; Variable selection
Interactions between species can alter selection on sexual displays used in mate choice within species. Here we study the epicuticular pheromones of two Drosophila species that overlap partially in geographic range and are incompletely reproductively isolated. Drosophila subquinaria shows a pattern of reproductive character displacement against Drosophila recens, and partial behavioral isolation between conspecific sympatric versus allopatric populations, whereas D. recens shows no such variation in mate choice. First, using manipulative perfuming experiments, we show that females use pheromones as signals for mate discrimination both between species and among populations of D. subquinaria. Second, we show that patterns of variation in epicuticular compounds, both across populations and between species, are consistent with those previously shown for mating probabilities: pheromone compositions differ between populations of D. subquinaria that are allopatric versus sympatric with D. recens, but are similar across populations of D. recens regardless of overlap with D. subquinaria. We also identify differences in pheromone composition among allopatric regions of D. subquinaria. In sum, our results suggest that epicuticular compounds are key signals used by females during mate recognition, and that these traits have diverged among D. subquinaria populations in response to reinforcing selection generated by the presence of D. recens.
PMCID: PMC4278427  PMID: 24351014
Mate choice; pheromones; reinforcement; sexual selection; speciation
7.  Modification of the Association Between Obesity and Lethal Prostate Cancer by TMPRSS2:ERG  
TMPRSS2:ERG is a hormonally regulated gene fusion present in about half of prostate tumors. We investigated whether obesity, which deregulates several hormonal pathways, interacts with TMPRSS2:ERG to impact prostate cancer outcomes.
The study included 1243 participants in the prospective Physicians’ Health Study and Health Professionals Follow-Up Study diagnosed with prostate cancer between 1982 and 2005. ERG overexpression (a TMPRSS2:ERG marker) was assessed by immunohistochemistry of tumor tissue from radical prostatectomy or transurethral resection of the prostate. Body mass index (BMI) and waist circumference, measured on average 1.3 years and 5.3 years before diagnosis, respectively, were available from questionnaires. Data on BMI at baseline was also available. We used Cox regression to calculate hazard ratios and 95% confidence intervals (CIs). All statistical tests were two-sided.
During a mean follow-up of 12.8 years, 119 men developed lethal disease (distant metastases or prostate cancer death). Among men with ERG-positive tumors, the multivariable hazard ratio for lethal prostate cancer was 1.48 (95% CI = 0.98 to 2.23) per 5-unit increase in BMI before diagnosis, 2.51 (95% CI = 1.26 to 4.99) per 8-inch increase in waist circumference before diagnosis, and 2.22 (95% CI = 1.35 to 3.63) per 5-unit increase in BMI at baseline. The corresponding hazard ratios among men with ERG-negative tumors were 1.10 (95% CI = 0.76 to1.59; P interaction = .24), 1.14 (95% CI = 0.62 to 2.10; P interaction = .09), and 0.78 (95% CI = 0.52 to 1.19; P interaction = .001).
These results suggest that obesity is linked with poorer prostate cancer prognosis primarily in men with tumors harboring the gene fusion TMPRSS2:ERG.
PMCID: PMC3866157  PMID: 24292212
8.  Prostate-specific membrane antigen protein expression in tumor tissue and risk of lethal prostate cancer 
Over-expression of prostate-specific membrane antigen (PSMA) in tumor tissue and serum has been linked to increased risk of biochemical recurrence in surgically treated prostate cancer patients, but no studies have assessed its association with disease-specific mortality.
We examined whether high PSMA protein expression in prostate tumor tissue was associated with lethal disease, and with tumor biomarkers of progression, among participants of two US-based cohorts (n=902, diagnosed 1983–2004). We used Cox proportional hazards regression to calculate multivariable hazard ratios (HR) and 95% confidence intervals (CI) of lethal prostate cancer, defined as disease-specific death or development of distant metastases (n=95). Partial Spearman rank correlation coefficients were used to correlate PSMA with tumor biomarkers.
During an average 13 years of follow-up, higher PSMA expression at prostatectomy was significantly associated with lethal prostate cancer (age-adjusted HRQuartile(Q)4vs.Q1=2.42; p-trend<0.01). This association was attenuated and non-significant (multivariable-adjusted HRQ4vs.Q1=1.01; p-trend=0.52) after further adjusting for Gleason score and PSA at diagnosis. High PSMA expression was significantly (p<0.05) correlated with higher Gleason score and PSA at diagnosis, increased tumor angiogenesis, lower vitamin D receptor and androgen receptor expression, and absence of ERG expression.
High tumor PSMA expression was not an independent predictor of lethal prostate cancer in the current study. PSMA expression likely captures, in part, malignant features of Gleason grade and tumor angiogenesis.
PSMA is not a strong candidate biomarker for predicting prostate cancer-specific mortality in surgically treated patients.
PMCID: PMC3893763  PMID: 24130224
prostate-specific membrane antigen; prostate cancer; tumor biomarkers; prognosis; angiogenesis
9.  Insulin, Insulin-like Growth Factor-I, Endogenous Estradiol, and Risk of Colorectal Cancer in Postmenopausal Women 
Cancer research  2008;68(1):329-337.
Obesity is a risk factor for colorectal cancer, and hyperinsulinemia, a common condition in obese patients, may underlie this relationship. Insulin, in addition to its metabolic effects, has promitotic and antiapoptotic activity that may be tumorigenic. Insulin-like growth factor (IGF)-I, a related hormone, shares sequence homology with insulin, and has even stronger mitogenic effects. However, few prospective colorectal cancer studies directly measured fasting insulin, and none evaluated free IGF-I, or endogenous estradiol, a potential cofactor in postmenopausal women. Therefore, we conducted a case-cohort investigation of colorectal cancer among nondiabetic subjects enrolled in the Women’s Health Initiative Observational Study, a prospective cohort of 93,676 postmenopausal women. Fasting baseline serum specimens from all incident colorectal cancer cases (n = 438) and a random subcohort (n = 816) of Women’s Health Initiative Observational Study subjects were tested for insulin, glucose, total IGF-I, free IGF-I, IGF binding protein-3, and estradiol. Comparing extreme quartiles, insulin [hazard ratio (HR)q4–q1, 1.73; 95% confidence interval (CI), 1.16–2.57; ptrend = 0.005], waist circumference (HRq4–q1, 1.82; 95% CI, 1.22–2.70; ptrend = 0.001), and free IGF-I (HRq4–q1, 1.35; 95% CI, 0.92–1.98; Ptrend = 0.05) were each associated with colorectal cancer incidence in multivariate models. However, these associations each became nonsignificant when adjusted for one another. Endogenous estradiol levels, in contrast, were positively associated with risk of colorectal cancer (HR comparing high versus low levels, 1.53; 95% CI, 1.05–2.22), even after control for insulin, free IGF-I, and waist circumference. These data suggest the existence of at least two independent biological pathways that are related to colorectal cancer: one that involves endogenous estradiol, and a second pathway broadly associated with obesity, hyperinsulinemia, and free IGF-I.
PMCID: PMC4225702  PMID: 18172327
10.  Interquantile Shrinkage in Regression Models 
Conventional analysis using quantile regression typically focuses on fitting the regression model at different quantiles separately. However, in situations where the quantile coefficients share some common feature, joint modeling of multiple quantiles to accommodate the commonality often leads to more efficient estimation. One example of common features is that a predictor may have a constant effect over one region of quantile levels but varying effects in other regions. To automatically perform estimation and detection of the interquantile commonality, we develop two penalization methods. When the quantile slope coefficients indeed do not change across quantile levels, the proposed methods will shrink the slopes towards constant and thus improve the estimation efficiency. We establish the oracle properties of the two proposed penalization methods. Through numerical investigations, we demonstrate that the proposed methods lead to estimations with competitive or higher efficiency than the standard quantile regression estimation in finite samples. Supplemental materials for the article are available online.
PMCID: PMC3867140  PMID: 24363546
Fused lasso; Non-crossing; Oracle; Quantile regression; Smoothing; Sup-norm
11.  Blood Levels of Saturated and Monounsaturated Fatty Acids as Markers of De Novo Lipogenesis and Risk of Prostate Cancer 
American Journal of Epidemiology  2013;178(8):1246-1255.
De novo lipogenesis has been implicated in prostate carcinogenesis, and blood levels of specific saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) could reflect activity of this pathway. We used gas chromatography to measure blood SFA and MUFA levels in prediagnostic samples from 476 incident prostate cancer cases (1982–1995) in the Physicians' Health Study and an equal number of controls matched on age and smoking status. Five tagging polymorphisms in the fatty acid synthase (FASN) gene (rs1127678, rs6502051, rs4246444, rs12949488, and rs8066956) were related to blood SFA and MUFA levels. Conditional logistic regression was used to estimate the rate ratios, with 95% confidence intervals, of prostate cancer across quintiles of blood fatty acid levels. The polymorphisms rs6502051 and rs4246444 were associated with lower levels of 14:1n-5, 16:1n-7, and 18:1n-9. Blood levels of 16:1n-7 were associated with higher prostate cancer incidence, with rate ratios for men in increasing quintiles of 1.00, 1.40, 1.35, 1.44, and 1.97 (95% confidence interval: 1.27–3.06; Ptrend = 0.003). Furthermore, 16:1n-7 levels were positively related to incidence of high-grade (Gleason score ≥7) tumors (rate ratioQ5–Q1 = 3.92; 95% confidence interval: 1.72–8.94) but not low-grade tumors (rate ratioQ5–Q1 = 1.51; 95% confidence interval: 0.87–2.62) (Pheterogeneity = 0.02). Higher activity of enzymes involved in de novo lipogenesis, as reflected in blood levels of 16:1n-7, could be involved in the development of high-grade prostate cancer.
PMCID: PMC3792734  PMID: 23989197
biomarkers; epidemiology; fatty acids; nutrition; prostate cancer
13.  A Prospective Study of Plasma Vitamin D Metabolites, Vitamin D Receptor Gene Polymorphisms, and Risk of Hypertension in Men 
European journal of nutrition  2012;52(7):1771-1779.
Laboratory studies have suggested that vitamin D inadequacy may be implicated in development of hypertension. Evidence from epidemiologic studies remains limited. We aim to examine the prospective associations of circulating vitamin D metabolites, vitamin D receptor (VDR) gene polymorphisms, and their interaction with risk of hypertension.
We conducted prospective analyses among 1,211 US men that were free of baseline hypertension and had baseline plasma 25hydroxy-vitamin D (25(OH)D) or 1,25dihydroxy-vitamin D (1,25(OH)2D) measured and VDR BsmI or FokI polymorphisms genotyped.
During 15.3-year follow-up, 695 men developed incident hypertension. After multivariable adjustment, the hazard ratios (HRs) and 95% CIs for hypertension across increasing quartiles of circulating vitamin D metabolites were 1.00 (ref), 0.94 (0.69–1.27), 0.69 (0.50–0.96), and 0.82 (0.60–1.13) for 25(OH)D (p, trend: 0.43), and 1.00, 0.92 (0.66–1.27), 1.12 (0.82–1.54), and 1.19 (0.86–1.63) for 1,25(OH)2D (p, trend: 0.16). Compared with carriers of VDR BsmI bb, carriers of bB or BB had a HR of 1.25 (1.04–1.51) for hypertension. For VDR FokI polymorphism, compared with carriers of FF and Ff combined, carriers of ff had a HR of 1.32 (1.03–1.70). The relation between plasma 25(OH)D and risk of hypertension did not differ by VDR BsmI and FokI polymorphisms.
In a prospective cohort of men, we found suggestive evidence for an inverse association between plasma 25(OH)D and risk of hypertension. We also found associations between VDR BsmI and FokI polymorphisms with hypertension risk. More research is needed to further determine the role of vitamin D in hypertension prevention.
PMCID: PMC3609910  PMID: 23262750
vitamin D; polymorphisms; prospective study; hypertension; men
14.  Circulating pro-surfactant protein B as a risk biomarker for lung cancer 
Our prior studies of lung cancer suggested that a novel biomarker (pro-surfactant protein B or pro-SFTPB) might serve as a predictive marker for this disease. We aimed to determine the potential utility of pro-SFTPB for distinguishing lung cancer cases from matched controls as a risk marker.
Study subjects were drawn from the longitudinal Physicians’ Health Study (PHS). Cases (n = 188) included individuals who were cancer-free at study enrollment but developed lung cancer during follow-up. Controls (n = 337) were subjects who did not develop lung cancer. Cases and controls were matched on date of study enrollment, age at enrollment, and smoking status and amount. Baseline plasma samples drawn at enrollment were analyzed for pro-SFTPB using ELISA to detect differences in protein expression levels for cases and controls.
Pro-SFTPB-non-detectable status was significantly associated with lung cancer risk (OR = 5.88, 95% CI 1.24, 27.48). Among subjects with detectable levels of the protein, increasing plasma concentration of pro-SFTPB was associated with higher lung cancer risk (OR = 1.41 per unit increase in log pro-SFTPB, 95% CI 1.08, 1.84).
These results suggest a non-linear, J-shaped association between plasma pro-SFTPB levels and lung cancer risk, with both non-detectable and higher levels of the marker being associated with lung cancer.
These results show promise of a risk marker that could contribute to predicting risk for lung cancer development and to narrowing the high risk population for low-dose computed tomography (LDCT) screening.
PMCID: PMC3866965  PMID: 23897585
Proteomics; cancer risk; biomarker; lung cancer
15.  Complete binasal hemianopia 
Binasal hemianopia is a rarely encountered visual field defect. We examined two asymptomatic female patients, aged 17 and 83, with complete binasal hemianopia. Both patients had unremarkable eye exams except for the visual field deficits and minimally reduced visual acuity and color vision. Both patients had normal neuroimaging. These are the first reported cases of complete binasal visual field defects without an identifiable ocular or neurologic cause.
PMCID: PMC4255866  PMID: 25484511
16.  Carotid-cavernous fistula as a mimicker of myasthenia gravis 
A carotid-cavernous fistula (CCF) is an abnormal communication between the carotid arterial system and the cavernous sinus. Common symptoms of CCFs include proptosis and ophthalmoplegia, but fluctuating diplopia and presence of ptosis are not typical.
Case Description:
We present an unusual case of CCF with fluctuating binocular diplopia and ptosis, mimicking myasthenia gravis. Electrodiagnostic testing, which included repetitive nerve stimulation and single-fiber electromyography, was normal. Magnetic resonance imaging of the brain and orbits was initially normal, but later magnetic resonance angiography revealed enlargement of the left superior ophthalmic vein along with a left CCF. Patient underwent a successful left cavernous sinus embolization.
Fluctuating ophthalmic symptoms are a typical presentation of myasthenia gravis; however, there may be an association of these symptoms with a CCF. Repetitive nerve stimulation and single-fiber electromyography played a key role in diagnosis of this case, as the normal result led to further investigations revealing a CCF.
PMCID: PMC4192903  PMID: 25317355
Carotid-cavernous fistula; fluctuating ophthalmic symptoms; myasthenia gravis; repetitive nerve stimulation; single-fiber electromyography
19.  The role of insulin-like growth factor-I and its binding proteins in glucose homeostasis and type 2 diabetes 
This review addresses the possible role of the insulin-like growth factor (IGF)-axis in normal glucose homoeostasis and in the etiopathogenesis of type 2 diabetes. IGF-I, a peptide hormone, shares amino acid sequence homology with insulin and has insulin-like activity; most notably, the promotion of glucose uptake by peripheral tissues. Type 2 diabetes as well as pre-diabetic states, including impaired fasting glucose and impaired glucose tolerance, are associated cross-sectionally with altered circulating levels of IGF-I and its binding proteins (IGFBPs). Administration of recombinant human IGF-I has been reported to improve insulin sensitivity in healthy individuals as well as in patients with insulin resistance and type 2 diabetes. Further, IGF-I may have beneficial effects on systemic inflammation, a risk factor for type 2 diabetes, and on pancreatic β-cell mass and function. There is considerable inter-individual heterogeneity in endogenous levels of IGF-I and its binding proteins; however, the relationship between these variations and the risk of developing type 2 diabetes has not been extensively investigated. Large prospective studies are required to evaluate this association.
PMCID: PMC4153414  PMID: 19145587
insulin-like growth factor (IGF)-I; glucose; diabetes; IGFBP
20.  A nonparametric spatial model for periodontal data with non-random missingness 
Journal of the American Statistical Association  2013;108(503):10.1080/01621459.2013.795487.
Periodontal disease progression is often quantified by clinical attachment level (CAL) defined as the distance down a tooth’s root that is detached from the surrounding bone. Measured at 6 locations per tooth throughout the mouth (excluding the molars), it gives rise to a dependent data set-up. These data are often reduced to a one-number summary, such as the whole mouth average or the number of observations greater than a threshold, to be used as the response in a regression to identify important covariates related to the current state of a subject’s periodontal health. Rather than a simple one-number summary, we set forward to analyze all available CAL data for each subject, exploiting the presence of spatial dependence, non-stationarity, and non-normality. Also, many subjects have a considerable proportion of missing teeth which cannot be considered missing at random because periodontal disease is the leading cause of adult tooth loss. Under a Bayesian paradigm, we propose a nonparametric flexible spatial (joint) model of observed CAL and the location of missing tooth via kernel convolution methods, incorporating the aforementioned features of CAL data under a unified framework. Application of this methodology to a data set recording the periodontal health of an African-American population, as well as simulation studies reveal the gain in model fit and inference, and provides a new perspective into unraveling covariate-response relationships in presence of complexities posed by these data.
PMCID: PMC3839869  PMID: 24288421
Attachment level; Dirichlet process; Kernel convolution; Non-normality; Non-stationarity
21.  Increased NQO1 but Not c-MET and Survivin Expression in Non-Small Cell Lung Carcinoma with KRAS Mutations 
Cigarette smoking is one of the most significant public health issues and the most common environmental cause of preventable cancer deaths worldwide. EGFR (Epidermal Growth Factor Receptor)-targeted therapy has been used in the treatment of LC (lung cancer), mainly caused by the carcinogens in cigarette smoke, with variable success. Presence of mutations in the KRAS (Kirsten rat sarcoma viral oncogene homolog) driver oncogene may confer worse prognosis and resistance to treatment for reasons not fully understood. NQO1 (NAD(P)H:quinone oxidoreductase), also known as DT-diaphorase, is a major regulator of oxidative stress and activator of mitomycins, compounds that have been targeted in over 600 pre-clinical trials for treatment of LC. We sequenced KRAS and investigated expression of NQO1 and five clinically relevant proteins (DNMT1, DNMT3a, ERK1/2, c-MET, and survivin) in 108 patients with non-small cell lung carcinoma (NSCLC). NQO1, ERK1/2, DNMT1, and DNMT3a but not c-MET and survivin expression was significantly more frequent in patients with KRAS mutations than those without, suggesting the following: (1) oxidative stress may play an important role in the pathogenesis, worse prognosis, and resistance to treatment reported in NSCLC patients with KRAS mutations, (2) selecting patients based on their KRAS mutational status for future clinical trials may increase success rate, and (3) since oxidation of nucleotides also specifically induces transversion mutations, the high rate of KRAS transversions in lung cancer patients may partly be due to the increased oxidative stress in addition to the known carcinogens in cigarette smoke.
PMCID: PMC4199031  PMID: 25222473
lung cancer; non-small cell lung carcinoma; oxidative stress; KRAS; mutation; NQO1; DNA methyl transferase; ERK1/2; c-MET; survivin
22.  Gleason Grade Progression Is Uncommon 
Cancer research  2013;73(16):5163-5168.
Gleason grade is universally used for pathologic scoring the differentiation of prostate cancer. However, it is unknown whether prostate tumors arise well-differentiated and then progress to less differentiated forms or if Gleason grade is an early and largely unchanging feature. Prostate Specific Antigen (PSA) screening has reduced the proportion of tumors diagnosed at advanced stage, which allows assessment of this question on a population level. If Gleason grade progresses as stage does, one would expect a similar reduction in high grade tumors. We studied 1,207 Physicians’ Health Study and Health Professionals Follow-up Study participants diagnosed with prostate cancer 1982–2004 and treated with prostatectomy. We compared the distribution of grade and clinical stage across the pre-PSA and PSA screening eras. We re-reviewed grade using the ISUP 2005 revised criteria. The proportion of advanced stage tumors dropped more than six-fold, from the earliest period (12/1982–1/1993), 19.9% stage ≥T3, to the latest (5/2000–12/2004), 3% stage T3, none T4. The proportion of Gleason score ≥8 decreased substantially less, from 25.3% to 17.6%. A significant interaction between stage and diagnosis date predicting grade (p=0.04) suggests the relationship between grade and stage varies by time period. As the dramatic shift in stage since the introduction of PSA screening was accompanied by a more modest shift in Gleason grade, these findings suggest grade may be established early in tumor pathogenesis. This has implications for the understanding of tumor progression and prognosis, and may help patients diagnosed with lower grade disease feel more comfortable choosing active surveillance.
PMCID: PMC3775342  PMID: 23946472
prostate cancer; Gleason score; dedifferentiation
23.  Hyperglycemia, Insulin Resistance, Impaired Pancreatic β-Cell Function, and Risk of Pancreatic Cancer 
Obesity and diabetes mellitus are associated with an increased risk of pancreatic cancer. These associations may be secondary to consequences of peripheral insulin resistance, pancreatic β-cell dysfunction, or hyperglycemia itself. Hemoglobin A1c (HbA1c) is a measure of hyperglycemia, whereas plasma insulin and proinsulin are markers of peripheral insulin resistance, and the proinsulin to insulin ratio marks pancreatic β-cell dysfunction.
This was a prospective, nested case-control study of 449 case patients and 982 control subjects with prediagnostic blood samples and no diabetes history from five prospective US cohorts followed through 2008. Two or three control subjects were matched to each case patient by year of birth, cohort, smoking, and fasting status. Pancreatic cancer risk was assessed by prediagnostic HbA1c, insulin, proinsulin, and proinsulin to insulin ratio with multivariable-adjusted logistic regression. All P values were two-sided.
The highest vs lowest quintiles of HbA1c, insulin, and proinsulin were associated with with an increased risk for pancreatic cancer (odds ratio [OR] = 1.79; 95% confidence interval [CI] = 1.17 to 2.72, P trend = .04 for HbA1c; OR = 1.57; 95% CI = 1.08 to 2.30; Ptrend = .002 for insulin; and OR = 2.22; 95% CI = 1.50 to 3.29; P trend < .001 for proinsulin). Proinsulin to insulin ratio was not associated with pancreatic cancer risk. Results were similar across studies (all P heterogeneity > .29). In cancers developing 10 or more years after blood collection, the associations with insulin and proinsulin became stronger (highest vs lowest quintile, OR = 2.77; 95% CI = 1.28 to 5.99 for insulin and OR = 3.60; 95% CI = 1.68 to 7.72 for proinsulin). In mutually adjusted models including HbA1c, insulin, and proinsulin, only proinsulin remained statistically significant ( highest vs lowest quintile, OR = 2.55; 95% CI = 1.54 to 4.21; Ptrend < .001).
Among participants from five large prospective cohorts, circulating markers of peripheral insulin resistance, rather than hyperglycemia or pancreatic β-cell dysfunction, were independently associated with pancreatic cancer risk.
PMCID: PMC3714020  PMID: 23847240
24.  Concomitant anal and cervical human papillomavirusV infections and intraepithelial neoplasia in HIV-infected and uninfected women 
AIDS (London, England)  2013;27(11):1743-1751.
To assess factors associated with concomitant anal and cervical human papillomavirus (HPV) infections in HIV-infected and at-risk women.
A study nested within the Women’s Interagency HIV Study (WIHS), a multi-center longitudinal study of HIV-1 infection in women conducted in six centers within the United States.
Four hundred and seventy HIV-infected and 185 HIV-uninfected WIHS participants were interviewed and examined with anal and cervical cytology testing. Exfoliated cervical and anal specimens were assessed for HPV using PCR and type-specific HPV testing. Women with abnormal cytologic results had colposcopy or anoscopy-guided biopsy of visible lesions. Logistic regression analyses were performed and odds ratios (ORs) measured the association for concomitant anal and cervical HPV infection.
One hundred and sixty-three (42%) HIV-infected women had detectable anal and cervical HPV infection compared with 12 (8%) of the HIV-uninfected women (P <0.001). HIV-infected women were more likely to have the same human papillomavirus (HPV) genotype in the anus and cervix than HIV-uninfected women (18 vs. 3%, P <0.001). This was true for both oncogenic (9 vs. 2%, P = 0.003) and nononcogenic (12 vs. 1%, P <0.001) HPV types. In multivariable analysis, the strongest factor associated with both oncogenic and nononcogenic concomitant HPV infection was being HIV-infected (OR = 4.6 and OR = 16.9, respectively). In multivariable analysis of HIV-infected women, CD4+ cell count of less than 200 was the strongest factor associated with concomitant oncogenic (OR = 4.2) and nononcogenic (OR = 16.5) HPV infection.
HIV-infected women, particularly those women with low CD4+ cell counts, may be good candidates for HPV screening and monitoring for both cervical and anal disease
PMCID: PMC3917497  PMID: 23803793
anal intraepithelial neoplasia; cervical intraepithelial neoplasia; HIV-infection; human papillomavirus; women
25.  Patient Reported Outcomes of a Randomized, Placebo-Controlled Trial of Bevacizumab in the Front-Line Treatment of Ovarian Cancer: A Gynecologic Oncology Group Study 
Gynecologic oncology  2012;128(3):573-578.
To analyze quality of life (QOL) in a randomized, placebo-controlled phase III trial concluding that the addition of concurrent and maintenance bevacizumab (Arm 3) to carboplatin and paclitaxel prolongs progression-free survival in front-line treatment of advanced ovarian cancer compared to chemotherapy alone (Arm 1) or chemotherapy with bevacizumab in cycles 2–6 only (Arm 2).
Patients and Methods
The Trial Outcome Index of the Functional Assessment of Cancer Therapy-Ovary (FACT-O TOI) was used to assess QOL before cycles 1, 4, 7, 13, and 21; and 6 months after completing study therapy. Differences in QOL scores were assessed using a linear mixed model, adjusting for baseline score, and age. The significance level was set at 0.0167 to account for multiple comparisons.
1693 patients were queried. Arm 2 (p<0.001) and Arm 3 (p<0.001) reported lower QOL scores than those in Arm 1. The treatment differences were observed mainly at cycle 4, when the patients receiving bevacizumab (Arm 2 and Arm 3) reported 2.72 points (98.3% CI: 0.88 ~ 4.57; effect size=0.18) and 2.96 points (98.3% CI: 1.13~4.78; effect size=0.20) lower QOL respectively, than those in Arm 1. The difference in QOL scores between Arm 1 and Arm 3 remained statistically significant up to cycle 7. The percentage of patients who reported abdominal discomfort dropped over time, without significant differences among study arms.
The small QOL difference observed during chemotherapy did not persist during maintenance bevacizumab.
PMCID: PMC4099057  PMID: 23219660

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