UW Neurological Surgery Recent PubMed Publications

Unravelling subclonal heterogeneity and aggressive disease states in TNBC through single-cell RNA-seq.

Nat Commun. 2018 Sep 04;9(1):3588

Authors: Karaayvaz M, Cristea S, Gillespie SM, Patel AP, Mylvaganam R, Luo CC, Specht MC, Bernstein BE, Michor F, Ellisen LW

Abstract
Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by extensive intratumoral heterogeneity. To investigate the underlying biology, we conducted single-cell RNA-sequencing (scRNA-seq) of >1500 cells from six primary TNBC. Here, we show that intercellular heterogeneity of gene expression programs within each tumor is variable and largely correlates with clonality of inferred genomic copy number changes, suggesting that genotype drives the gene expression phenotype of individual subpopulations. Clustering of gene expression profiles identified distinct subgroups of malignant cells shared by multiple tumors, including a single subpopulation associated with multiple signatures of treatment resistance and metastasis, and characterized functionally by activation of glycosphingolipid metabolism and associated innate immunity pathways. A novel signature defining this subpopulation predicts long-term outcomes for TNBC patients in a large cohort. Collectively, this analysis reveals the functional heterogeneity and its association with genomic evolution in TNBC, and uncovers unanticipated biological principles dictating poor outcomes in this disease.

PMID: 30181541 [PubMed - in process]

The relationship between defense mechanisms and religious coping using a new two-factor solution for the Defense Style Questionnaire-40.

Bull Menninger Clin. 2018;82(3):224-252

Authors: Prout TA, Gottdiener WH, Camargo A, Murphy S

Abstract
This study examined the factor structure of the Defense Style Questionnaire (DSQ-40) and explored the relationships between defense mechanisms and religious coping in a diverse sample of 380 college students. In contrast with the three-factor model of defenses proposed by the developers of the DSQ-40, principal axis factoring yielded two internally consistent components: adaptive and maladaptive defense styles. Endorsement of adaptive defenses was positively correlated with the use of positive religious coping strategies and negatively correlated with negative religious coping. Maladaptive defenses were associated with the endorsement of negative religious coping strategies. Clinical implications of these findings are discussed and recommendations are made for future use of the DSQ-40.

PMID: 30179043 [PubMed - indexed for MEDLINE]

Does the future of laparoscopic sleeve gastrectomy lie in the outpatient surgery center? A retrospective study of the safety of 3162 outpatient sleeve gastrectomies.

Surg Obes Relat Dis. 2018 Oct;14(10):1442-1447

Authors: Surve A, Cottam D, Zaveri H, Cottam A, Belnap L, Richards C, Medlin W, Duncan T, Tuggle K, Zorak A, Umbach T, Apel M, Billing P, Billing J, Landerholm R, Stewart K, Kaufman J, Harris E, Williams M, Hart C, Johnson W, Lee C, Lee C, DeBarros J, Orris M, Schniederjan B, Neichoy B, Dhorepatil A, Cottam S, Horsley B

Abstract
BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is a safe and effective procedure that can be performed as an outpatient procedure.
OBJECTIVES: The aim of the study was to determine whether same-day discharge LSG is safe when performed in an outpatient surgery center.
SETTING: Outpatient surgery centers.
METHODS: The medical records of 3162 patients who underwent primary LSG procedure by 21 surgeons at 9 outpatient surgery centers from January 2010 through February 2018 were retrospectively reviewed.
RESULTS: Three thousand one hundred sixty-two patients were managed with enhanced recovery after surgery protocol and were included in this analysis. The mean age and preoperative body mass index were 43.1 ± 10.8 years and 42.1 ± 7.1 kg/m2, respectively. Sleep apnea, type 2 diabetes, gastroesophageal reflux disease, hypertension, and hyperlipidemia were seen in 14.4%, 13.5%, 24.7%, 30.4%, and 17.6% patients, respectively. The mean total operative time was 56.4 ± 16.9 minutes (skin to skin). One intraoperative complication (.03%) occurred. The hospital transfer rate was .2%. The 30-day follow-up rate was 85%. The postoperative outcomes were analyzed based on the available data. The 30-day readmission, reoperation, reintervention, and emergency room visit rates were .6%, .6%, .2%, and .1%, respectively. The 30-day mortality rate was 0%. The total short-term complication rate was 2.5%.
CONCLUSIONS: Same-day discharge seems to be safe when performed in an outpatient surgery center in selected patients. It would appear that outpatient surgery centers are a viable option for patients with minimal surgical risks.

PMID: 30170954 [PubMed - indexed for MEDLINE]

Method and Apparatus for the Automated Delivery of Continuous Neural Stem Cell Trails Into the Spinal Cord of Small and Large Animals.

Neurosurgery. 2019 10 01;85(4):560-573

Authors: Kutikov AB, Moore SW, Layer RT, Podell PE, Sridhar N, Santamaria AJ, Aimetti AA, Hofstetter CP, Ulich TR, Guest JD

Abstract
BACKGROUND: Immature neurons can extend processes after transplantation in adult animals. Neuronal relays can form between injected neural stem cells (NSCs) and surviving neurons, possibly improving recovery after spinal cord injury (SCI). Cell delivery methods of single or multiple bolus injections of concentrated cell suspensions thus far tested in preclinical and clinical experiments are suboptimal for new tract formation. Nonuniform injectate dispersal is often seen due to gravitational cell settling and clumping. Multiple injections have additive risks of hemorrhage, parenchymal damage, and cellular reflux and require additional surgical exposure. The deposition of multiply delivered cells boluses may be uneven and discontinuous.
OBJECTIVE: To develop an injection apparatus and methodology to deliver continuous cellular trails bridging spinal cord lesions.
METHODS: We improved the uniformity of cellular trails by formulating NSCs in hyaluronic acid. The TrailmakerTM stereotaxic injection device was automatized to extend a shape memory needle from a single-entry point in the spinal cord longitudinal axis to "pioneer" a new trail space and then retract while depositing an hyaluronic acid-NSC suspension. We conducted testing in a collagen spinal models, and animal testing using human NSCs (hNSCs) in rats and minipigs.
RESULTS: Continuous surviving trails of hNSCs within rat and minipig naive spinal cords were 12 and 40 mm in length. hNSC trails were delivered across semi-acute contusion injuries in rats. Transplanted hNSCs survived and were able to differentiate into neural lineage cells and astrocytes.
CONCLUSION: The TrailmakerTM creates longitudinal cellular trails spanning multiple levels from a single-entry point. This may enhance the ability of therapeutics to promote functional relays after SCI.

PMID: 30169668 [PubMed - indexed for MEDLINE]

Microsurgical Excision of T12-L1 Pial Arteriovenous Malformation: 3-Dimensional Operative Video.

Oper Neurosurg (Hagerstown). 2018 Aug 30;:

Authors: Zeeshan Q, Cheng CY, Ghodke BV, Sekhar LN

Abstract
This 29-yr-old man presented with progressive paraparesis, sensory loss, allodynia, bowel, and bladder dysfunction for 9 mo, acutely exacerbated in the preceding 24 h. Magnetic resonance imaging scan showed multiple dilated vessels involving the thoracic cord. Spinal angiogram revealed a T12-L1 pial arteriovenous malformation (AVM)/arteriovenous fistula on the left side. It was fed by an L1 radicular artery that filled the anterior spinal artery, which in turn had multiple feeders to a pial AVM. Because of the supply from the anterior spinal artery with multiple feeders to the AVM, and the danger of infarction of the conus, embolization was not performed.He underwent T11-L1 laminectomy laterally to the pedicles and excision of AVM. There was one large arterialized vein in the midline that had a fistulous connection with an artery coursing up from inferiorly. Despite occlusion of this fistula, the vein was still arterialized. On further exploration, there was a large artery coming in to the subarachnoid space at the T11 level and coursing inferiorly, and entering the intradural pial AVM with a glomus of vessels located at the T12 level in the left anterolateral subpial aspect of the cord. This major artery as well as multiple smaller vessels going into it were cauterized and divided, and the AVM was totally excised.Postoperative angiogram showed complete excision of the nidus. At 1 mo follow-up, he had complete recovery of motor and bladder functions but bowel dysfunction persisted. He was independent for his daily activities.Informed consent was obtained from the patient prior to the surgery that included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.

PMID: 30169720 [PubMed - as supplied by publisher]

Sternocleidomastoid Encephalomyosynangiosis for Treatment-Resistant Moyamoya Disease.

Oper Neurosurg (Hagerstown). 2019 07 01;17(1):E23-E28

Authors: Chiarelli PA, Patel AP, Lee A, Chandra SR, Sekhar LN

Abstract
BACKGROUND AND IMPORTANCE: Refractory ischemic symptoms in moyamoya disease are a challenging problem, particularly in situations in which multiple direct and indirect revascularization techniques have already been employed. In addition, revascularization of the parietal lobes is difficult, as this area is a watershed between the middle cerebral artery and posterior cerebral artery distributions.
CLINICAL PRESENTATION: This is the case of a 50-yr-old woman with hemibody sensorimotor deficits, who had previously undergone bilateral arterial bypass and temporalis myosynangiosis. A method for indirect surgical cerebral revascularization is described, utilizing a rotated and tunneled sternocleidomastoid flap. The perfused muscle is approximated to the cortical surface, with adjacent sulci dissected to expose the underlying vasculature. After sternocleidomastoid encephalomyosynangiosis, the patient experienced symptomatic improvement, along with the appearance of new pial collateral vasculature on diagnostic cerebral angiography. Pre- and postoperative dynamic perfusion computed tomography with acetazolamide challenge demonstrate an increase in cerebral blood flow and decrease in mean transit time, as well as improved cerebrovascular reserve.
CONCLUSION: Sternocleidomastoid encephalomyosynangiosis using a tunneled muscle flap is a useful method for revascularization of the parietal and occipital lobes, particularly for refractory moyamoya in cases where a variety of other options have been exhausted.

PMID: 30169838 [PubMed - indexed for MEDLINE]

Characterization of the immune microenvironment of diffuse intrinsic pontine glioma: implications for development of immunotherapy.

Neuro Oncol. 2019 01 01;21(1):83-94

Authors: Lieberman NAP, DeGolier K, Kovar HM, Davis A, Hoglund V, Stevens J, Winter C, Deutsch G, Furlan SN, Vitanza NA, Leary SES, Crane CA

Abstract
Background: Diffuse intrinsic pontine glioma (DIPG) is a uniformly fatal CNS tumor diagnosed in 300 American children per year. Radiation is the only effective treatment and extends overall survival to a median of 11 months. Due to its location in the brainstem, DIPG cannot be surgically resected. Immunotherapy has the ability to target tumor cells specifically; however, little is known about the tumor microenvironment in DIPGs. We sought to characterize infiltrating immune cells and immunosuppressive factor expression in pediatric low- and high-grade gliomas and DIPG.
Methods: Tumor microarrays were stained for infiltrating immune cells. RNA was isolated from snap-frozen tumor tissue and Nanostring analysis performed. DIPG and glioblastoma cells were co-cultured with healthy donor macrophages, T cells, or natural killer (NK) cells, and flow cytometry and cytotoxicity assays performed to characterize the phenotype and function, respectively, of the immune cells.
Results: DIPG tumors do not have increased macrophage or T-cell infiltration relative to nontumor control, nor do they overexpress immunosuppressive factors such as programmed death ligand 1 and/or transforming growth factor β1. H3.3-K27M DIPG cells do not repolarize macrophages, but are not effectively targeted by activated allogeneic T cells. NK cells lysed all DIPG cultures.
Conclusions: DIPG tumors have neither a highly immunosuppressive nor inflammatory microenvironment. Therefore, major considerations for the development of immunotherapy will be the recruitment, activation, and retention of tumor-specific effector immune cells.

PMID: 30169876 [PubMed - indexed for MEDLINE]

Analysis and visualization of linked molecular and clinical cancer data by using Oncoscape.

Nat Genet. 2018 09;50(9):1203-1204

Authors: McFerrin LG, Zager M, Zhang J, Krenn G, McDermott R, Horse-Grant D, Silgard E, Colevas K, Shannon P, Bolouri H, Holland EC

PMID: 30158685 [PubMed - indexed for MEDLINE]

Anal squamous cell carcinoma: are we improving outcomes?

ANZ J Surg. 2018 10;88(10):1013-1016

Authors: Mackowski A, Levitt M, Makin G, Salama P, Tan P, Penter C, Platell C

Abstract
BACKGROUND: Anal squamous cell carcinoma (SCC) is a rare malignancy. The purpose of this study was to review a single institution's experience.
METHODS: All patients with anal SCC from St John of God Subiaco Hospital database were identified over a 10-year period (2006-2016). Patients with stage 1 anal verge tumours underwent wide local excision, all remaining patients were offered chemoradiation (CRT) as an initial treatment modality (a fluorouracil-based regimen in conjunction with mitomycin). Outcomes included recurrence, overall survival and survival following salvage surgery.
RESULTS: Forty-seven patients were identified. Median age was 60 years and median follow-up was 2.73 years. Five-year rates of recurrence and overall survival were 35.8% (95% confidence interval (CI) 23.2-52.4%) and 65.4% (95% CI 47.0-78.7%), respectively. Locoregional failure occurred most commonly at the primary site. Eight patients underwent salvage abdominoperineal resection for persistent or recurrent disease, and four of these patients died within 5 years.
CONCLUSION: CRT is a proven and reasonable effective approach in managing anal cancer. Observed recurrence and overall survival rates in this study resemble the published data. Despite newer methods of treatment being investigated, the treatment for anal SCC has not significantly changed in the past four decades and novel approaches are needed to further improve outcomes.

PMID: 30159994 [PubMed - indexed for MEDLINE]

Periodontitis and multiple markers of cardiometabolic risk in the fourth decade: A cohort study.

Community Dent Oral Epidemiol. 2018 12;46(6):615-623

Authors: Shearer DM, Thomson WM, Cameron CM, Ramrakha S, Wilson G, Wong TY, Williams MJA, McLean R, Theodore R, Poulton R

Abstract
OBJECTIVES: To examine associations between periodontitis at ages 32 and 38 and a range of early cardiometabolic risk biomarkers at age 38.
METHODS: Periodontal probing depth and bleeding on probing data collected during the age-32 and age-38 assessments in the Dunedin Multidisciplinary Health and Development Study were used to quantify periodontal inflammatory load. Retinal microvascular abnormalities, endothelial dysfunction, and metabolic syndrome data were collected during the age-38 assessment. Regression models were used to examine associations between these cardiometabolic risk markers and (1) the inflammatory load at age 38 and (2) the change in inflammatory load between ages 32 and 38.
RESULTS: Periodontal inflammatory load was recorded for 890 Study members at age 32, 891 at age 38, and 856 at both ages. Retinal vessel data were available for 922, endothelial dysfunction data for 909 and metabolic syndrome data for 905 at age 38. Neither the inflammatory load of periodontitis at 38 nor the changes in inflammatory load 32-38 were found to be associated with any of the three cardiometabolic risk markers.
CONCLUSIONS: Periodontitis was not associated with markers of cardiometabolic risk at this relatively early stage in the life course. It is possible that any influence of periodontitis on cardiometabolic health develops later in life, or periodontitis is not involved in the putative causal chain comprising systemic inflammation, cardiometabolic risk markers, and subsequent cardiovascular risk.

PMID: 30160305 [PubMed - indexed for MEDLINE]

MAP1B mutations cause intellectual disability and extensive white matter deficit.

Nat Commun. 2018 Aug 27;9(1):3456

Authors: Walters GB, Gustafsson O, Sveinbjornsson G, Eiriksdottir VK, Agustsdottir AB, Jonsdottir GA, Steinberg S, Gunnarsson AF, Magnusson MI, Unnsteinsdottir U, Lee AL, Jonasdottir A, Sigurdsson A, Jonasdottir A, Skuladottir A, Jonsson L, Nawaz MS, Sulem P, Frigge M, Ingason A, Love A, Norddhal GL, Zervas M, Gudbjartsson DF, Ulfarsson MO, Saemundsen E, Stefansson H, Stefansson K

Abstract
Discovery of coding variants in genes that confer risk of neurodevelopmental disorders is an important step towards understanding the pathophysiology of these disorders. Whole-genome sequencing of 31,463 Icelanders uncovers a frameshift variant (E712KfsTer10) in microtubule-associated protein 1B (MAP1B) that associates with ID/low IQ in a large pedigree (genome-wide corrected P = 0.022). Additional stop-gain variants in MAP1B (E1032Ter and R1664Ter) validate the association with ID and IQ. Carriers have 24% less white matter (WM) volume (β = -2.1SD, P = 5.1 × 10-8), 47% less corpus callosum (CC) volume (β = -2.4SD, P = 5.5 × 10-10) and lower brain-wide fractional anisotropy (P = 6.7 × 10-4). In summary, we show that loss of MAP1B function affects general cognitive ability through a profound, brain-wide WM deficit with likely disordered or compromised axons.

PMID: 30150678 [PubMed - in process]

Cerebrospinal Fluid Shunting Complications in Children.

Pediatr Neurosurg. 2017;52(6):381-400

Authors: Hanak BW, Bonow RH, Harris CA, Browd SR

Abstract
Although cerebrospinal fluid (CSF) shunt placement is the most common procedure performed by pediatric neurosurgeons, shunts remain among the most failure-prone life-sustaining medical devices implanted in modern medical practice. This article provides an overview of the mechanisms of CSF shunt failure for the 3 most commonly employed definitive CSF shunts in the practice of pediatric neurosurgery: ventriculoperitoneal, ventriculopleural, and ventriculoatrial. The text has been partitioned into the broad modes of shunt failure: obstruction, infection, mechanical shunt failure, overdrainage, and distal catheter site-specific failures. Clinical management strategies for the various modes of shunt failure are discussed as are research efforts directed towards reducing shunt complication rates. As it is unlikely that CSF shunting will become an obsolete procedure in the foreseeable future, it is incumbent on the pediatric neurosurgery community to maintain focused efforts to improve our understanding of and management strategies for shunt failure and shunt-related morbidity.

PMID: 28249297 [PubMed - indexed for MEDLINE]

Predictors of tobacco and alcohol co-use from ages 15 to 32: The Amsterdam Growth and Health Longitudinal Study.

Exp Clin Psychopharmacol. 2018 Dec;26(6):549-559

Authors: McPherson SM, Burduli E, Smith CL, Brooks O, Orr MF, Barbosa-Leiker C, Hoekstra T, McDonell MG, Murphy SM, Layton M, Roll JM

Abstract
Tobacco and alcohol are often used in tandem over time, but specific predictors of course and patterns of course over time need explication. We examined differences in alcohol and tobacco course among an adolescent population as they transitioned into young adulthood across a 17-year period. Data came from participants (n = 303 for ages 15-21, n = 196 for ages 21 to 32; 52% female and 54% female, respectively) enrolled in the Amsterdam Growth and Health Longitudinal Study, an epidemiologic investigation examining disease across the life span. We utilized parallel latent growth modeling to assess the impact of sex, personality traits, cholesterol, blood pressure, and body mass index (BMI), on initial status and linear change over time in course of tobacco and alcohol. Females reported less alcohol use at adolescent baseline (β = -21.79), less increase during adolescence (β = -7.92, p < .05), slower decrease during young adulthood (β = 4.67, p < .05), and more rapid decline in tobacco use during young adulthood (β = -70.85, p < .05), relative to males. Alcohol and tobacco use baseline status' and change over time were all significantly associated with one another during both adolescence and young adulthood (p < .05; aside from alcohol baseline and slope during young adulthood). Effects of BMI, cholesterol, blood pressure, and personality traits were also observed on tobacco and alcohol course. In light of the strong, but sex dependent relationship between alcohol and tobacco course, particularly from ages 15 to 21, prevention efforts to curb heavy alcohol and tobacco use should consider targeting course taking into account biological sex and other notable covariates. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

PMID: 30148405 [PubMed - indexed for MEDLINE]

CT cervico-cerebral angiography in acute stroke. Can we justify aortic arch imaging?

Ir J Med Sci. 2019 May;188(2):661-666

Authors: Sugrue G, O'Reilly MK, Byrne D, Crockett MT, Murphy S, Kavanagh EC

Abstract
OBJECTIVES: Computed tomography cervico-cerebral angiography (CTCCA) plays a pivotal role in the evaluation of acute stroke. Currently no evidence justifies the inclusion of the upper chest in the CTCCA field of view. The aim of this study was to assess the prevalence and clinical significance of vascular findings identified on CTCCA in the head, neck, and upper chest regions in patients presenting with acute stroke symptoms.
METHODS: A retrospective review of radiology images and reports of 900 consecutive patients (425 men, 475 women; mean age 63.2 years, age range 19-99 years) with a suspected acute stroke who underwent CTCCA in the emergency department between January 2011 and July 2016. Clinically significant vascular CTCCA findings were recorded for each patient within the head, neck, and upper chest regions, respectively.
RESULTS: Of the 900 patients, clinically significant vascular CTCCA findings were identified in 404/900 (44.8%) patients. 218/900 (24.2%) were located within the head region; 174/900 (19.3%) within the neck; and 12/900 (2.4%) in the upper chest. Of the 12 vascular findings located within the upper chest, 3/900 (0.33%) were related to a clinically significant posterior circulation infarct.
CONCLUSIONS: Routine inclusion of the upper chest on CTCCA is currently difficult to justify in the evaluation of a suspected acute anterior circulation stroke, contributing significantly to total radiation dose without demonstrating significant extra-cranial vascular findings. Prospective studies adopting narrower fields of view excluding the upper chest are necessary.

PMID: 30143966 [PubMed - indexed for MEDLINE]

Inside out: Repurposing endobronchial intubation to facilitate extraluminal placement of a 5 Fr Arndt bronchial blocker in young infants.

Paediatr Anaesth. 2018 07;28(7):668-669

Authors: Templeton TW, Lawrence AE, Lee AJ, Templeton LB

PMID: 30133914 [PubMed - indexed for MEDLINE]

A Preregistered Study of Competing Predictions Suggests That Men Do Overestimate Women's Sexual Intent.

Psychol Sci. 2017 02;28(2):253-255

Authors: Murray DR, Murphy SC, von Hippel W, Trivers R, Haselton MG

PMID: 28056212 [PubMed - indexed for MEDLINE]

Factors Affecting Stereotactic Accuracy in Image-Guided Deep Brain Stimulator Electrode Placement.

Stereotact Funct Neurosurg. 2017;95(5):315-324

Authors: Ko AL, Ibrahim A, Magown P, Macallum R, Burchiel KJ

Abstract
BACKGROUND/AIMS: Intraoperative imaging allows near-real-time assessment of stereotactic accuracy during implantation of deep brain stimulation (DBS) electrodes. Such technology can be used to examine factors impacting stereotactic error.
METHODS: Intraoperative CT imaging was reviewed in patients undergoing DBS placement at Oregon Health and Sciences University. Coordinates of the target electrode were compared to the operative plan to characterize the magnitude and direction of stereotactic error with respect to side of implantation, target, and electrode approach angles.
RESULTS: One hundred sixty-nine leads in 94 patients were examined. Targets were GPi (n = 86), STN (n = 31), and Vim (n = 52). The average Euclidean error was 1.63 mm (SD 0.87). The error magnitude was higher for Vim (1.95 mm) than for GPi (1.44 mm), while STN (1.65 mm) did not differ from either Vim or GPi (ANOVA: F = 6.15, p = 0.003). Electrodes targeting Vim and STN were significantly more likely to deviate medially compared to those targeting GPi (ANOVA: F = 9.13, p < 0.001). The coronal approach angle affected the error when targeting Vim (ρ = 0.338, p = 0.01). These findings were confirmed during multivariate analyses.
CONCLUSIONS: This study shows a significant effect of target on the accuracy of electrode placement for DBS. Targeting Vim results in a greater Euclidean error and a greater medial deviation off target. These systematic deviations should be taken into account during electrode implantation.

PMID: 28889124 [PubMed - indexed for MEDLINE]

Tracking large Anterior Mitral Leaflet displacements by incorporating optical flow in an active contours framework.

Conf Proc IEEE Eng Med Biol Soc. 2017 07;2017:3244-3247

Authors: Saad Sultan M, Martins N, Costa E, Veiga D, Ferreira MJ, Mattos S, Tavares Coimbra M

Abstract
Echocardiography is an important tool to detect early evidence of mitral valve degradation associated with rheumatic heart disease. The segmentation and tracking of the Anterior Mitral Leaflet helps to quantify the morphologic valve anomalies, such as the leaflet thickening, shape and the mobility changes. The tracking of this leaflet throughout the cardiac cycle is still an open challenge in the research community. The widely used active contours segmentation framework fails when faced with large leaflet displacement. In this work, we propose the integration of optical flow in an open-ended active contour framework to address this difficulty. This additional information promotes solutions with contours next to high leaflet displacements, resulting in superior performance. The algorithm was tested on 9 fully annotated real clinical videos, acquired from the parasternal long axis view. The algorithm is compared with our previous work. Results show a clear improvement in situations where the leaflet exhibits large displacement or irregular shapes, with an average error of 4.5 pixels and a standard deviation of 2 pixels.

PMID: 29060589 [PubMed - indexed for MEDLINE]

Bridging the HIV-syphilis testing gap: dual testing among men who have sex with men living in China.

Sex Transm Infect. 2019 06;95(4):251-253

Authors: Ong JJ, Liao M, Lee A, Fu H, Pan SW, Tang W, Wei C, Dan W, Yang B, Yang L, Wang C, Tucker JD

Abstract
OBJECTIVES: The WHO recommends dual testing for HIV and syphilis among key populations, including men who have sex with men (MSM). We assessed the proportion of men who had dual tested and reasons for not dual testing.
METHODS: In 2017, an online survey of MSM was conducted in eight cities from two provinces in China. Data on sociodemographics and sexual behaviours were collected. Descriptive analysis was used to examine the experience of dual testing. Multivariable logistic regression identified characteristics associated with men who had dual tested.
RESULTS: Among 802 men who had ever tested for HIV, 297 dual tested (37%, 95% CI 34 to 40). Men dual tested in a variety of settings: public hospital (35%), voluntary counselling and testing sites (28%), self-testing at home (18%), community-based organisation (8%), community health centre (7%), other (3%) or private hospital (1%). Greater odds for dual testing was found in men who had disclosed their sexuality to a healthcare provider (adjusted OR (AOR) 1.81, 95% CI 1.27 to 2.59, p=0.001), and who had substantial (AOR 2.71, 95% CI 1.67 to 4.41, p<0.001) or moderate community engagement in sexual health (AOR 2.30, 95% CI 1.49 to 3.57, p<0.001), compared with those with no community engagement. The most common reasons for not dual testing were no knowledge that they could be dual tested (34%), did not ask the doctor to be dual tested (25%) and did not believe they were at risk for syphilis (19%).
CONCLUSIONS: Chinese MSM are dual testing through a variety of test sites, including home self-testing. However, the overall dual testing rate remains low despite recent efforts to integrate HIV and syphilis testing.

PMID: 30126948 [PubMed - indexed for MEDLINE]

On the importance of accounting for nuclear quantum effects in ab initio calibrated force fields in biological simulations.

Proc Natl Acad Sci U S A. 2018 09 04;115(36):8878-8882

Authors: Pereyaslavets L, Kurnikov I, Kamath G, Butin O, Illarionov A, Leontyev I, Olevanov M, Levitt M, Kornberg RD, Fain B

Abstract
In many important processes in chemistry, physics, and biology the nuclear degrees of freedom cannot be described using the laws of classical mechanics. At the same time, the vast majority of molecular simulations that employ wide-coverage force fields treat atomic motion classically. In light of the increasing desire for and accelerated development of quantum mechanics (QM)-parameterized interaction models, we reexamine whether the classical treatment is sufficient for a simple but crucial chemical species: alkanes. We show that when using an interaction model or force field in excellent agreement with the "gold standard" QM data, even very basic simulated properties of liquid alkanes, such as densities and heats of vaporization, deviate significantly from experimental values. Inclusion of nuclear quantum effects via techniques that treat nuclear degrees of freedom using the laws of classical mechanics brings the simulated properties much closer to reality.

PMID: 30127031 [PubMed - indexed for MEDLINE]