Secukinumab in patients with moderate-to-severe hidradenitis suppurativa based on prior biologic exposure: an efficacy and safety analysis from the SUNSHINE and SUNRISE phase III trials.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease associated with a substantial disease burden. Secukinumab has previously been reported to have sustained efficacy with a favourable safety profile in patients with moderate-to-severe HS. It is unknown whether prior biologic exposure affects the efficacy and safety of secukinumab. OBJECTIVES: To investigate the efficacy and safety of secukinumab in patients with moderate-to-severe HS based on prior exposure to -biologics. METHODS: This was an analysis of the SUNSHINE and SUNRISE phase III trials of secukinumab in patients with moderate-to-severe HS. Patients were randomized at baseline to receive secukinumab every 2 (SECQ2W) or 4 weeks (SECQ4W), or placebo for 16 weeks. After week 16, patients on the SECQ2W and SECQ4W schedules remained on the same treatment regimen, while patients randomized to placebo were switched to either SECQ2W or SECQ4W up to week 52. Assessments based on prior exposure to biologics included Hidradenitis Suppurativa Clinical Response (HiSCR), abscess and inflammatory nodule (AN) count, flare rates, HS-related pain [numerical rating scale 30 (NRS30)], 55% reduction in the International Hidradenitis Suppurativa Severity Score System (IHS4-55), Dermatology Life Quality Index, EuroQol-5D and safety. RESULTS: Overall, 1084 patients were randomized in the SUNSHINE and SUNRISE trials and included in this analysis; 255 (23.5%) were biologic-experienced [SECQ2W (n = 80); SECQ4W (n = 81); placebo (n = 94)] and 829 (76.5%) were biologic-naïve [SECQ2W (n = 281); SECQ4W (n = 279); placebo (n = 269)]. At week 16, responses were more efficacious for secukinumab than for placebo with regard to HiSCR in patients who were biologic-experienced {SECQ2W 37.0% [odds ratio (OR) 1.60, 95% confidence interval (CI) 0.83-3.08]; SECQ4W 38.8% [OR 1.67, 95% CI 0.86-3.22]; placebo 27.3%} and biologic-naïve [SECQ2W 45.6% (OR 1.64, 95% CI 1.15-2.33); SECQ4W 45.4% (OR 1.61, 95% CI 1.13-2.29); placebo 34.2%]. Similar results were observed for AN count, NRS30 and IHS4-55. The higher response seen at week 16 with secukinumab was sustained, with a trend toward improvement over time, through to week 52 in both subgroups. Additional efficacy was observed for quality-of-life assessments, and no differences in safety between subgroups were observed. CONCLUSIONS: Regardless of prior biologic exposure, secukinumab was efficacious in improving the signs and symptoms of HS. This finding positions secukinumab as the first option in patients who are biologic-naïve, as well as in patients who have previously been treated with other biologic therapy, based on individual patient needs.

Hidradenitis suppurativa (HS) is a chronic skin disease that causes painful boils. HS is common and affects about 0.4% of the world's population. Treating the condition is difficult, but drugs called 'biologics' can help to improve the symptoms. For example, secukinumab is a biologic drug that has been shown to be effective and well-tolerated for the treatment of HS. In this analysis, we investigated whether previous treatment with biologics could affect the effectiveness and tolerability of secukinumab. This analysis included data from two identical clinical trials (called SUNSHINE and SUNRISE) that recruited adult patients with HS who had moderate-to-severe disease. In these trials, patients took secukinumab 300 mg every 2 weeks or every 4 weeks for 1 year, or a placebo for 4 months and then switched to secukinumab until 1 year. At regular intervals, the effectiveness and tolerability of secukinumab were examined and the results were compared between patients who had previously used another biologic and patients who had never used a biologic before. After 16 weeks, patients who took secukinumab had better results than the patients who took a placebo, independent of previous biologic use. Secukinumab was still effective and had improved results over 1 year of treatment in both subgroups. Regardless of whether patients had previously been taking another biologic, secukinumab was just as tolerable as placebo and there were no new safety risks. Our analysis shows that secukinumab is effective and tolerable, regardless of whether patients have previously used another biologic drug.

Clinical Characteristics and Outcomes of Eyes with Intraocular Inflammation after Brolucizumab: Post Hoc Analysis of HAWK and HARRIER.

PURPOSE: This analysis of the pivotal phase 3 HAWK and HARRIER trials aimed to provide insights on the timing of presentation, management, and outcomes of intraocular inflammation (IOI)-related adverse events (AEs), as reported by investigators in these trials. DESIGN: Post hoc analysis of investigator-reported IOI-related AEs in HAWK and HARRIER. PARTICIPANTS: Of 1088 brolucizumab-treated eyes (3 or 6 mg), 49 eyes demonstrated at least 1 IOI-related AE and were included in this analysis. METHODS: Reports of IOI-related AEs were analyzed and descriptive statistics were provided for outcome measures. MAIN OUTCOME MEASURES: Incidence and description of eyes with IOI-related AEs, timing of presentation, management, clinical outcomes, and brolucizumab treatment after the first IOI-related AE. RESULTS: Seventy IOI-related AEs were reported in 49 eyes. Before the onset of first IOI-related AE, eyes received a mean ± standard deviation (SD) of 3.9 ± 2.2 brolucizumab injections. Median time to first IOI-related AE from the last administered brolucizumab injection was 18.0 days (interquartile range, 4.0-29.0 days). Of the 70 AEs, 61 (87.1%) were treated, most with topical corticosteroids; systemic and intraocular corticosteroids were used for 3 AEs each. Overall, inflammation resolved completely in 39 eyes (79.6%), resolved with sequelae in 5 eyes (10.2%), and did not resolve in 5 eyes (10.2%) by end-of-study (EOS). Overall, the mean ± SD best-corrected visual acuity (BCVA) change from baseline to EOS, before AE to the lowest BCVA in 3 months after AE, and from before AE to EOS were -0.84 ± 20.6 , -16.31 ± 17.6, and -0.22 ± 18.9 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, respectively. Of the 36 eyes (73.5%) that continued with brolucizumab therapy after the first IOI-related AE, 24 completed the trials and 12 discontinued; mean ± SD BCVA change in these eyes was 2.6 ± 17.6, 7.8 ± 13.2, and -7.7 ± 21.3 ETDRS letters, respectively, from baseline to EOS. The remaining 13 eyes (26.5%) were not treated with brolucizumab after first IOI-related AE and showed a mean ± SD BCVA change of -10.4 ± 25.5 ETDRS letters from baseline to EOS. CONCLUSIONS: Findings of this analysis highlight the need for continued vigilance and monitoring for any signs of IOI-related events in patients receiving brolucizumab.

Reach, engagement and effectiveness of in-person and online lifestyle change programs to prevent diabetes.

BACKGROUND: COVID-19 has accelerated interest in and need for online delivery of healthcare. We examined the reach, engagement and effectiveness of online delivery of lifestyle change programs (LCP) modelled after the Diabetes Prevention Program (DPP) in a multistate, real-world setting. METHODS: Longitudinal, non-randomized study comparing online and in-person LCP in a large multistate sample delivered over 1 year. Sample included at-risk adults (n = 26,743) referred to online (n = 9) and in-person (n = 11) CDC-recognized LCP from a multi-state registry (California, Florida and Colorado) between 2015 and 2018. The main outcome was effectiveness (proportion achieving > 5% weight loss) at one-year. Our secondary outcomes included reach (proportion enrolled among referred) and engagement (proportion ≥ 9 sessions by week 26). We used logistic regression modelling to assess the association between participant- and setting -level characteristics with meaningful weight loss. RESULTS: Online LCP effectiveness was lower, with 23% of online participants achieving > 5% weight loss, compared with 35% of in-person participants (p < 0.001). More adults referred to online programs enrolled (56% vs 51%, p < 0.001), but fewer engaged at 6-months (attendance at ≥9 sessions 46% vs 66%, p < 0.001) compared to in-person participants. CONCLUSIONS: Compared to adults referred to in-person LCP, those referred to online LCP were more likely to enroll and less likely to engage. Online participants achieved modest meaningful weight loss. Online delivery of LCP is an attractive strategy to deliver and scale DPP, particularly with social distancing measures currently in place. However, it is unclear how to optimize delivery models for maximal impact given trade-offs in reach and effectiveness.

Post-lumpectomy breast calcifications: Can original tumor features assist in determining need for biopsy?

OBJECTIVE: The objective of our study was to determine whether, in the digital era, imaging features of a primary breast tumor can be used to influence the decision to biopsy ipsilateral breast calcifications that occur following surgery in women treated with breast conservation surgery (BCS). MATERIALS AND METHODS: We retrospectively identified women treated with BCS who subsequently developed suspicious calcifications in the treated breast (BI-RADS 4 or 5) from January 2012 - December 2018. Only cases with histopathological diagnosis by stereotactic or surgical biopsy were included. Pathology reports were reviewed, and biopsy results were considered malignant if invasive carcinoma or ductal carcinoma in situ (DCIS) was found. All other results were considered benign. Fisher's exact test was done comparing frequencies of malignancy between those patients whose original tumor had calcifications versus those whose original tumors were not calcified. RESULTS: Of 90 women with suspicious calcifications on a post-BCS mammogram, 65 (72.2%) were biopsy proven benign and 25 (27.8%) were malignant. The original tumor presented without calcifications in 39 patients (43%), and 51 (57%) had calcifications with or without associated mass, focal asymmetry, or architectural distortion. New calcifications were less likely to be malignant if the original tumor presented without calcifications (5/39; 12.8%) as compared to original tumors with calcifications (20/51; 38.5%) [p-value < 0.05]. CONCLUSION: New calcifications after BCS are significantly less likely to be malignant if the original tumor presented without calcifications. However, with a PPV of 12.8%, even calcifications in a patient with a non-calcified primary tumor require biopsy.

Diagnostic Accuracy of Amyloid versus 18 F-Fluorodeoxyglucose Positron Emission Tomography in Autopsy-Confirmed Dementia.

OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy of antemortem 11 C-Pittsburgh compound B (PIB) and 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) versus autopsy diagnosis in a heterogenous sample of patients. METHODS: One hundred one participants underwent PIB and FDG PET during life and neuropathological assessment. PET scans were visually interpreted by 3 raters blinded to clinical information. PIB PET was rated as positive or negative for cortical retention, whereas FDG scans were read as showing an Alzheimer disease (AD) or non-AD pattern. Neuropathological diagnoses were assigned using research criteria. Majority visual reads were compared to intermediate-high AD neuropathological change (ADNC). RESULTS: One hundred one participants were included (mean age = 67.2 years, 41 females, Mini-Mental State Examination = 21.9, PET-to-autopsy interval = 4.4 years). At autopsy, 32 patients showed primary AD, 56 showed non-AD neuropathology (primarily frontotemporal lobar degeneration [FTLD]), and 13 showed mixed AD/FTLD pathology. PIB showed higher sensitivity than FDG for detecting intermediate-high ADNC (96%, 95% confidence interval [CI] = 89-100% vs 80%, 95% CI = 68-92%, p = 0.02), but equivalent specificity (86%, 95% CI = 76-95% vs 84%, 95% CI = 74-93%, p = 0.80). In patients with congruent PIB and FDG reads (77/101), combined sensitivity was 97% (95% CI = 92-100%) and specificity was 98% (95% CI = 93-100%). Nine of 24 patients with incongruent reads were found to have co-occurrence of AD and non-AD pathologies. INTERPRETATION: In our sample enriched for younger onset cognitive impairment, PIB-PET had higher sensitivity than FDG-PET for intermediate-high ADNC, with similar specificity. When both modalities are congruent, sensitivity and specificity approach 100%, whereas mixed pathology should be considered when PIB and FDG are incongruent. ANN NEUROL 2021;89:389-401.

A second X chromosome contributes to resilience in a mouse model of Alzheimer's disease.

A major sex difference in Alzheimer's disease (AD) is that men with the disease die earlier than do women. In aging and preclinical AD, men also show more cognitive deficits. Here, we show that the X chromosome affects AD-related vulnerability in mice expressing the human amyloid precursor protein (hAPP), a model of AD. XY-hAPP mice genetically modified to develop testicles or ovaries showed worse mortality and deficits than did XX-hAPP mice with either gonad, indicating a sex chromosome effect. To dissect whether the absence of a second X chromosome or the presence of a Y chromosome conferred a disadvantage on male mice, we varied sex chromosome dosage. With or without a Y chromosome, hAPP mice with one X chromosome showed worse mortality and deficits than did those with two X chromosomes. Thus, adding a second X chromosome conferred resilience to XY males and XO females. In addition, the Y chromosome, its sex-determining region Y gene (Sry), or testicular development modified mortality in hAPP mice with one X chromosome such that XY males with testicles survived longer than did XY or XO females with ovaries. Furthermore, a second X chromosome conferred resilience potentially through the candidate gene Kdm6a, which does not undergo X-linked inactivation. In humans, genetic variation in KDM6A was linked to higher brain expression and associated with less cognitive decline in aging and preclinical AD, suggesting its relevance to human brain health. Our study suggests a potential role for sex chromosomes in modulating disease vulnerability related to AD.

A systematic review and meta-analysis examining the effects of cannabis and its derivatives in adults with malignant CNS tumors.

BACKGROUND: Primary CNS tumors constitute a heterogeneous group of neoplasms that share a considerable morbidity and mortality rate. To help control tumor growth and clinical outcomes (overall survival, progression-free survival, quality of life) symptoms, patients often resort to alternative therapies, including the use of cannabis. Despite rapidly growing popularity, cannabis and its impact on patients with primary malignant CNS tumors is understudied. METHODS: To shed light on the lack of scientific evidence in this field, in November 2018 we conducted a search and examination of cannabis in neuro-oncology in major journal databases and bibliographies of selected articles, and through abstracts of annual meetings using prespecified criteria in line with the Cochrane Collaboration guidelines. RESULTS: We identified 45 publications, of which 9 were selected. Five studies were included. Publication dates ranged from 2004 to 2018 and included varying histologies of primary brain tumors. The average survival at 1 year was 56.09% (95% CI: 48.28-63.9). There was no difference in risk ratio (RR) for death at 1 year between groups (RR: 1.069 [95% CI: 0.139-8.25]). We found strong evidence of heterogeneity (Q = 74.0%; P = .021). We found no statistical evidence of publication bias (P = .117; SD = 1.91). CONCLUSIONS: There was limited moderate-quality evidence that supports the use of cannabinoids as adjuvant to the standard of care in the treatment of brain and CNS tumors. There was very low-quality evidence suggesting that cannabinoids were associated with adult-onset gliomas. Further prospective clinical trials are necessary to adequately evaluate the impact of cannabinoids on CNS tumors, specifically on survival and quality of life.

Performance of screening MRI in high risk patients at initial versus subsequent screen.

PURPOSE: To compare the characteristics, outcomes, and performance metrics in women undergoing initial breast MRI screening versus subsequent screening. METHODS: A retrospective database search identified screening MRIs performed at an academic practice from 2013 to 2015. MRIs were divided into two groups: (1) initial screens and (2) subsequent screens (interpreted with at least one prior MRI for comparison). Benignity was confirmed with pathology or >1-year follow-up. Malignancy was confirmed by pathology. Performance metrics were calculated. Comparisons were made using Binomial and Fisher's exact tests. RESULTS: We observed a higher rate of abnormal interpretations (52% vs. 19%; p < 0.001) and rate of biopsy (49% vs. 15%; p < 0.001) in the initial versus subsequent screen group. The positive predictive value of biopsy was slightly lower at initial versus subsequent screen (17% vs. 19%, p = 0.99). However, the cancer detection rate was higher at initial than at subsequent screen (85 vs. 29/1000, p = 0.08). Sensitivity was higher at initial (100%) versus subsequent (88%) screen. However, the specificity at initial screen was low (55%) compared to subsequent screen (83%). CONCLUSIONS: The higher rate of abnormal interpretations in the initial versus subsequent screen group in part reflects a prevalence screening. Although we observed more abnormal interpretations in the initial screen, this was likely justified by the significantly higher cancer detection. This evidence may be used to counsel patients and referring providers on the expected higher likelihood of recall from an initial screening MRI balanced with higher detection of malignancies. Findings also highlight the importance of having comparison MRIs to decrease false positives.

Factors Predicting Metastatic Disease in 68Ga-PSMA-11 PET-Positive Osseous Lesions in Prostate Cancer.

Bone is the most common site of distant metastatic spread in prostate adenocarcinoma. Prostate-specific membrane antigen (PSMA) uptake has been described in both benign and malignant bone lesions, which can lead to false-positive findings on 68Ga-PSMA-11 PET. The purpose of this study was to evaluate the diagnostic accuracy of 68Ga-PSMA-11 PET for osseous prostate cancer metastases and improve bone uptake interpretation using semiquantitative metrics. Methods: Fifty-six prostate cancer patients (18 before prostatectomy and 38 with biochemical recurrence) who underwent 68Ga-PSMA-11 PET/MRI or PET/CT examinations with osseous PSMA-ligand uptake were included in the study. Medical records were reviewed retrospectively by board-certified nuclear radiologists to determine true or false positivity based on a composite endpoint. For each avid osseous lesion, we measured biologic volume; size; PSMA Reporting and Data System (RADS) rating; SUVmax; and ratio of lesion SUVmax to liver, blood pool, and background bone SUVmax Differences between benign and malignant lesions were evaluated for statistical significance, and cutoffs for these parameters were determined to maximize diagnostic accuracy. Results: Among 56 participants, 13 (22.8%) had false-positive osseous 68Ga-PSMA-11 findings and 43 (76.8%) had true-positive osseous 68Ga-PSMA-11 findings. Twenty-two patients (39%) had 1 osseous lesion, 18 (32%) had 2-4 lesions, and 16 (29%) had 5 or more lesions. Cutoffs resulting in statistically significant (P < 0.005) differences between benign and malignant lesions were a PSMA RADS rating of at least 4, an SUVmax of at least 4.1, and SUVmax ratios of at least 2.11 for lesion to blood pool, at least 0.55 for lesion to liver, and at least 4.4 for lesion to bone. These measurements corresponded to a lesion-based 68Ga-PSMA-11 PET lesion detection rate of 80%, 93%, 89%, 21%, and 89%, respectively, for malignancy, and a specificity of 73%, 73%, 73%, 93%, and 60%, respectively. Conclusion: PSMA RADS rating, SUVmax, and SUVmax ratio for lesion to blood pool can help differentiate benign from malignant lesions on 68Ga-PSMA-11 PET. An SUVmax ratio of more than 2.2 for lesion to blood pool is a reasonable parameter to support image interpretation and presented a superior lesion detection rate and specificity when compared with visual interpretation by PSMA RADS. These parameters hold clinical value by improving diagnostic accuracy for metastatic prostate cancer on 68Ga-PSMA-11 PET/MRI and PET/CT.

Pathogenic DDX3X Mutations Impair RNA Metabolism and Neurogenesis during Fetal Cortical Development.

De novo germline mutations in the RNA helicase DDX3X account for 1%-3% of unexplained intellectual disability (ID) cases in females and are associated with autism, brain malformations, and epilepsy. Yet, the developmental and molecular mechanisms by which DDX3X mutations impair brain function are unknown. Here, we use human and mouse genetics and cell biological and biochemical approaches to elucidate mechanisms by which pathogenic DDX3X variants disrupt brain development. We report the largest clinical cohort to date with DDX3X mutations (n = 107), demonstrating a striking correlation between recurrent dominant missense mutations, polymicrogyria, and the most severe clinical outcomes. We show that Ddx3x controls cortical development by regulating neuron generation. Severe DDX3X missense mutations profoundly disrupt RNA helicase activity, induce ectopic RNA-protein granules in neural progenitors and neurons, and impair translation. Together, these results uncover key mechanisms underlying DDX3X syndrome and highlight aberrant RNA metabolism in the pathogenesis of neurodevelopmental disease.

Pericardial Fat Enhancement: New Computed Tomography Biomarker Influences the Relationship Between Pericardial Fat and Coronary Artery Disease.

PURPOSE: Studies have shown a modest association between pericardial fat volume (PFV) and coronary artery disease (CAD), potentially mediated by local inflammation. We aimed to investigate the association between a new biomarker of pericardial fat inflammation, named pericardial fat enhancement (PFE), and the severity of CAD on coronary computed tomography angiography (CCTA). MATERIALS AND METHODS: We evaluated 114 patients referred for CCTA from 2007 to 2011. PFV, presence of obstructive CAD, and the burden of CAD were determined. PFE was measured in 10 mm regions of interest, adjusted to aortic enhancement (aPFE). The population was divided into those with greater than median (G-PFE) versus less than median pericardial fat enhancement (L-PFE). Stratified adjusted logistic regressions were performed. A P-value <0.05 was considered significant. The study was approved by our institutional review board. RESULTS: Patients were 54.3±14.8 years of age, and 57/114 (50%) were male individuals, with body mass index of 27.3±6.3. There was an independent association between CAD severity and PFV. There was a significant independent association between PFV and obstructive CAD (odds ratio=1.26, P=0.005), and PFV and burden of CAD (odds ratio=1.25, P=0.05) in those with greater PFE. However, there was no significant association between obstructive CAD and CAD burden in either adjusted model for patients with less PFE. CONCLUSIONS: Our results suggest that PFE influences significantly the relationship between PFV and CAD, supporting the hypothesis of local pericardial fat inflammation as a mechanism for CAD development.

Case-control versus case-only estimates of gene-environment interactions with common and misclassified clinical diagnosis.

Genetic studies provide valuable information to assess if the effect of genetic variants varies by the nongenetic "environmental" variables, what is traditionally defined to be gene-environment interaction (GxE). A common complication is that multiple disease states present with the same set of symptoms, and hence share the clinical diagnosis. Because (a) disease states might have distinct genetic bases; and (b) frequencies of the disease states within the clinical diagnosis vary by the environmental variables, analyses of association with the clinical diagnosis as an outcome variable might result in false positive or false negative findings. We develop estimates for this setting to be able to assess GxE in a case-only study and we compare the case-control and case-only estimates. We report extensive simulation studies that evaluate empirical properties of the estimates and show the application to a study of Alzheimer's disease.

Hyperpolarized in vivo pH imaging reveals grade-dependent acidification in prostate cancer.

There is an unmet clinical need for new and robust imaging biomarkers to distinguish indolent from aggressive prostate cancer. Hallmarks of aggressive tumors such as a decrease in extracellular pH (pHe) can potentially be used to identify aggressive phenotypes. In this study, we employ an optimized, high signal-to-noise ratio hyperpolarized (HP) 13C pHe imaging method to discriminate between indolent and aggressive disease in a murine model of prostate cancer. Transgenic adenocarcinoma of the mouse prostate (TRAMP) mice underwent a multiparametric MR imaging exam, including HP [13C] bicarbonate MRI for pHe, with 1H apparent diffusion coefficient (ADC) mapping and HP [1-13C] pyruvate MRI to study lactate metabolism. Tumor tissue was excised for histological staining and qRT-PCR to quantify mRNA expression for relevant glycolytic enzymes and transporters. We observed good separation in pHe between low- and high-grade tumor regions, with high-grade tumors demonstrating a lower pHe. The pHe also correlated strongly with monocarboxylate transporter Mct4 gene expression across all tumors, suggesting that lactate export via MCT4 is associated with acidification in this model. Our results implicate extracellular acidification as an indicator of indolent-to-aggressive transition in prostate cancer and suggest feasibility of HP pHe imaging to detect high-grade, clinically significant disease in men as part of a multiparametric MRI examination.

A Simple Approximation to Bias in Gene-Environment Interaction Estimates When a Case Might Not Be the Case.

Case-control genetic association studies are often used to examine the role of the genetic basis in complex diseases, such as cancer and neurodegenerative diseases. The role of the genetic basis might vary by nongenetic (environmental) measures, what is traditionally defined as gene-environment interactions (G×E). A commonly overlooked complication is that the set of clinically diagnosed cases might be contaminated by a subset with a nuisance pathologic state that presents with the same symptoms as the pathologic state of interest. The genetic basis of the pathologic state of interest might differ from that of the nuisance pathologic state. Often, frequencies of the pathologically defined states within the clinically diagnosed set of cases vary by the environment. We derive a simple and general approximation to bias in G×E parameter estimates when the presence of the nuisance pathologic state is ignored. We then perform extensive simulation studies to show that ignoring the presence of the nuisance pathologic state can result in substantial bias in G×E estimates and that the approximation we derived is reasonably accurate in finite samples. We demonstrate the applicability of the proposed approximation in a study of Alzheimer's disease.

A simple approximation to bias in the genetic effect estimates when multiple disease states share a clinical diagnosis.

Case-control genome-wide association studies (CC-GWAS) might provide valuable clues to the underlying pathophysiologic mechanisms of complex diseases, such as neurodegenerative disease and cancer. A commonly overlooked complication is that multiple distinct disease states might present with the same set of symptoms and hence share a clinical diagnosis. These disease states can only be distinguished based on a biomarker evaluation that might not be feasible in the whole set of cases in the large number of samples that are typically needed for CC-GWAS. Instead, the biomarkers are measured on a subset of cases. Or an external reliability study estimates the frequencies of the disease states of interest within the clinically diagnosed set of cases. These frequencies often vary by the genetic and/or nongenetic variables. We derive a simple approximation that relates the genetic effect estimates obtained in a traditional logistic regression model with the clinical diagnosis as the outcome variable to the genetic effect estimates in the relationship to the true disease state of interest. We performed simulation studies to assess the accuracy of the approximation that we have derived. We next applied the derived approximation to the analysis of the genetic basis of the innate immune system of Alzheimer's disease.

The impact of technical parameters on ablation volume during MR-guided focused ultrasound of desmoid tumors.

PURPOSE: Desmoid tumors are benign, locally aggressive soft tissue tumors derived from fibroblasts. Magnetic resonance-guided focused ultrasound (MRgFUS) is a safe and effective treatment for desmoid tumors. The purpose of this study was to retrospectively review the MRgFUS treatments of desmoid tumors at our institution to determine which technical treatment parameters contributed most significantly to the accumulation of thermal dose. MATERIALS AND METHODS: The study protocol was approved by the local IRB. We retrospectively reviewed data from MRgFUS treatments performed in histologically-confirmed desmoid tumors, over a period of 18 months. Sonication parameter means were compared with ANOVA. Mixed effects and linear regression models were used to evaluate the relative contribution of different parameters to thermal dose volume. RESULTS: Nine-hundred thirty-six sonications were reviewed in 13 treatments. Accumulated dose per sonication was greatest for elongated sonications (0.96 cc ± 0.90) compared to short (0.88 ± 0.93 cc) and nominal (0.55 ± 0.70 cc) sonications, p < .001. 65.2% of short sonications resulted in high percentage ablations, compared to 46.0% of nominal and 35.1% of elongated sonications. Standardized beta coefficients (anticipated increased volume in cc per unit) for power, duration, energy and average temperature were 0.006, 0.057, 0.00035 and 0.03, p < .001. Regarding dose efficacy, dose area contributed the greatest to this variability - 50.7% (45.5-54.8%), followed by distance - 16.6% (12.9-20.0%). CONCLUSIONS: A variety of sonication parameters significantly contributed to thermal ablation volume following MRgFUS of desmoid tumors, in reproducible patterns. This work can serve as the basis for future models working toward improved planning for MRgFUS treatments.

A simple approximation to the bias of gene-environment interactions in case-control studies with silent disease.

One of the most important research areas in case-control Genome-Wide Association Studies is to determine how the effect of a genotype varies across the environment or to measure the gene-environment interaction (G × E). We consider the scenario when some of the "healthy" controls actually have the disease and when the frequency of these latent cases varies by the environmental variable of interest. In this scenario, performing logistic regression with the clinically diagnosed disease status as an outcome variable and will result in biased estimates of G × E interaction. Here, we derive a general theoretical approximation to the bias in the estimates of the G × E interaction and show, through extensive simulation, that this approximation is accurate in finite samples. Moreover, we apply this approximation to evaluate the bias in the effect estimates of the genetic variants related to mitochondrial proteins a large-scale prostate cancer study.

Female XX sex chromosomes increase survival and extend lifespan in aging mice.

Female longevity is observed in humans and much of the animal kingdom, but its causes remain elusive. Using a genetic manipulation that generates XX and XY mice, each with either ovaries or testes, we show that the female XX sex chromosome complement increases survival during aging in male and female mice. In combination with ovaries, it also extends lifespan. Understanding causes of sex-based differences in aging could lead to new pathways to counter age-induced decline in both sexes.