688 research outputs found

    Sequential Sectioning of the Ulnar Collateral Ligament of the Elbow in Cadaveric Arms with Ulnohumeral Laxity Assessed by Dynamic Ultrasonography

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    Objectives: Injury of the ulnar collateral ligament (UCL), whether acute or chronic, is potentially career-threatening for elite overhead throwing athletes. Dynamic ultrasound (DUS) allows for rapid, cost-effective, non-invasive, and non-radiating evaluation of the UCL and elbow joint both at rest and with applied stress. The purpose of this study was to determine the amount of cadaveric elbow valgus laxity with sequential UCL sectioning using DUS. Our objective was to quantify which portions of the UCL must be injured to cause the varying levels of laxity seen clinically on DUS testing. No prior study has used DUS to quantify valgus joint laxity with sequential cadaveric UCL sectioning. It was hypothesized that the change in laxity due to release of the anterior band of the UCL would be greater than that seen when the posterior and transverse bands were cut. Methods: Twelve cadaveric elbows were dissected free of skin and subcutaneous tissue by an experienced orthopaedic surgeon. Baseline DUS at rest and with applied valgus stress was then performed by an experienced ultrasonographer. Sequential sectioning of the medial elbow soft-tissue stabilizing structures was then carried out with valgus stress applied to the joint at each sectioning interval utilizing a standardized device (Telos, Marburg, Germany). First the transverse band of the UCL was released, followed by the posterior band, then the anterior bundle of the anterior band, the remaining posterior bundle of the anterior band, and finally the complete flexor pronator mass. Results: Mean ulnohumeral laxity in millimeters with 95% CIs was calculated for each step of the sequence. The deltas between each step of the dissection were also calculated with means and 95% CIs. Mean baseline laxity of the unstressed ulnohumeral joint at rest was 3.2 mm (CI, 2.2-4.2); with the addition of valgus stress, mean laxity was 4.7 mm (CI, 3.5-6.0). When the transverse band was cut, ulnohumeral laxity increased to a mean of 5.5 mm (CI, 4.0-7.0). With release of the posterior band, mean laxity was 6.4 mm (CI, 4.3-8.5). When the anterior bundle of the anterior band of the UCL was cut, mean ulnohumeral laxity was 8.4 mm (CI, 5.7-11.0) and when the entire anterior band was released, mean laxity was 10.9 mm (CI, 7.8-14.0). Complete release of the flexor pronator muscle mass resulted in mean ulnohumeral laxity of 15.5 mm (CI, 12.9-18.1). The largest deltas were observed with release of the anterior bundle of the anterior band (2.0 mm; CI, 1.0-3.0), the entire anterior band (2.6 mm; CI, 1.3-3.8), and flexor pronator mass (4.6 mm; CI, 1.3-3.8). Release of the transverse and posterior bands of the UCL resulted in deltas of 0.74 mm (CI, 0.1-1.3) and 0.9 mm (CI, 0.3-1.5) respectively. Conclusion: DUS allows for rapid, cost-effective, non-invasive, non-radiating evaluation of the elbow joint and UCL both at rest and with applied valgus stress. Previous studies have indicated that DUS can identify abnormalities of the UCL associated with chronic degeneration and ligamentous injury including thickening of the anterior band of the UCL as well as hypoechoic foci/calcifications. The results of the current cadaveric study suggest that different changes in clinical laxity are seen on DUS with injury of particular bands of the UCL. Early identification and localization of injury to a particular band of the UCL may allow more appropriate selection of patients who will benefit from operative treatment. © The Author(s) 2013

    Compiler-Aided Methodology for Low Overhead On-line Testing

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    Reliability is emerging as an important design criterion in modern systems due to increasing transient fault rates. Hardware fault-tolerance techniques, commonly used to address this, introduce high design costs. As alternative, software Signature-Monitoring (SM) schemes based on compiler assertions are an efficient method for control-flow-error detection. Existing SM techniques do not consider application-specific-information causing unnecessary overheads. In this paper, compile-time Control-Flow-Graph (CFG) topology analysis is used to place best-suited assertions at optimal locations of the assembly code to reduce overheads. Our evaluation with representative workloads shows fault-coverage increase with overheads close to Assertion- based Control-Flow Correction (ACFC), the method with lowest overhead. Compared to ACFC, our technique improves (on average) fault coverage by 17%, performance overhead by 5% and power-consumption by 3% with equal code-size overhead

    Spatial and temporal homogeneity of driver mutations in diffuse intrinsic pontine glioma.

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    Diffuse Intrinsic Pontine Gliomas (DIPGs) are deadly paediatric brain tumours where needle biopsies help guide diagnosis and targeted therapies. To address spatial heterogeneity, here we analyse 134 specimens from various neuroanatomical structures of whole autopsy brains from nine DIPG patients. Evolutionary reconstruction indicates histone 3 (H3) K27M-including H3.2K27M-mutations potentially arise first and are invariably associated with specific, high-fidelity obligate partners throughout the tumour and its spread, from diagnosis to end-stage disease, suggesting mutual need for tumorigenesis. These H3K27M ubiquitously-associated mutations involve alterations in TP53 cell-cycle (TP53/PPM1D) or specific growth factor pathways (ACVR1/PIK3R1). Later oncogenic alterations arise in sub-clones and often affect the PI3K pathway. Our findings are consistent with early tumour spread outside the brainstem including the cerebrum. The spatial and temporal homogeneity of main driver mutations in DIPG implies they will be captured by limited biopsies and emphasizes the need to develop therapies specifically targeting obligate oncohistone partnerships

    Вивчення впливу комбінованої дії фотосенсибілізатора і низькоінтенсивного лазерного випромінювання на кількісний склад мікрофлори зубного нальоту

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    The effect of low-intensity laser radiation (LILR) on the background of a photosensitizer (ethacridine lactate) on selective elimination of pathogenic and conditionally pathogenic microorganisms has been studied. Taking into account antiseptic properties of ethacridine lactate the maximally possible time of influence of ethacridine lactate as a photosensitizer should be set. It has been found that after the influence of rivanol (ethacridine lactate) within 1.5-3 minutes the bactericidal action on microorganisms is observed. The effect of antiseptic in the interval from 30 to 60 seconds was not accompanied with the expressed quantitative change of the microbial population. The second stage of the research was identification of microorganisms sensitivity to various concentrations of the photosensitizer. As a photosensitizer the aqueous solution of ethacridine lactate in the concentrations of 0.1; 0.05; 0.01% was used. The results obtained allow to conclude that the concentration of 0.1% solution of ethacridine lactate increases the sensitivity of microorganisms to the effects of low-intensity laser radiation. During the experiment the combined impact of the antimicrobial activity of 0.1% solution of ethacridine lactate and blue spectrum laser radiation has been determined; it is manifested by decrease in the number of CFU/ml of the total microflora of the dental plaque. The number of CFU is reduced from 14.3 ± 0.12 . 103/ml up to 2.4 ± 0.3 . 102/ml after exposure (Table 1). Comparing the data of the control (the initial number of the colonies grown) and the experiment (the number of the colonies grown after the photoactivated disinfection) we have found that the antibacterial action of photoactivated disinfection depends directly on duration of exposure. Thus, the effectiveness of combined use of a photosensitizer with LILR is 1.2 times higher than that of ethacridine lactate (the exposure time is 60 seconds), and 2.0 times higher than the antimicrobial effect of the laser blue spectrum (the exposure time is 120 seconds).В проведенном исследовании изучали влияние НИЛИ на фоне фотосенсибилизатора (этакридина лактата) на селективную элиминацию патогенных и условно-патогенных микроорганизмов. Учитывая то, что этакридина лактату присущи свойства антисептика, следовало установить максимально возможное время воздействия этакридина лактата как фотосенсибилизатора. Установлено, что после воздействия риванола (этакридина лактата) в течение 1,5-3-х минут отмечалось бактерицидное действие на микроорганизмы. Воздействие антисептика в промежутке от 30 до 60 с не сопровождалось выраженным количественным изменением микробной популяции. Вторым этапом исследования стало определение чувствительности микроорганизмов к различным концентрациям фотосенсибилизатора. Использовали водный раствор этакридина лактата с концентрациями 0,1; 0,05; 0,01%. Полученные результаты позволяют сделать вывод, что раствор этакридина лактата в концентрации 0,1% повышает чувствительность микроорганизмов к действию низкоинтенсивного лазерного излучения. В ходе проведенного эксперимента было установлено антимикробное действие комбинированного влияния 0,1%-ого раствора этакридина лактата и лазерного излучения синего спектра, что проявляется снижением числа КОЕ/мл совокупной микрофлоры зубного налёта. Количество КОЕ снижается со значения 14,3±0,12 × 103/мл до значения 2,4±0,3 × 102/мл после облучения. Сопоставляя данные контроля (исходное число выросших колоний) и опыта (число колоний, выросших после проведения фотоактивированной дезинфекции), мы установили, что антимикробное действие фотоактивированной дезинфекции находится в прямой зависимости от длительности облучения. Так, эффективность комбинированного использования фотосенсибилизатора с НИЛИ в 1,2 раза превышает активность этакридина лактата (время экспозиции – 60 с) и в 2,0 раза превышает противомикробный эффект лазерного излучения синего спектра (время экспозиции – 120 с).У проведеному дослідженні вивчали вплив НІЛВ на тлі фотосенсибілізатора (етакридину лактату) на селективну елімінацію патогенних і умовно-патогенних мікроорганізмів. Враховуючи те, що етакридину лактату притаманні властивості антисептика, слід було встановити максимально можливий час дії етакридину лактату як фотосенсибілізатора. Встановлено, що після дії риванолу (етакридину лактату) протягом 1,5-3-х хвилин відзначалася бактерицидна дія на мікроорганізми. Дія ж антисептика в проміжку від 30 до 60 с не супроводжувалася вираженою кількісною зміною мікробної популяції. Другим етапом дослідження стало визначення чутливості мікроорганізмів до різних концентрацій фотосенсибілізатора. Використали водний розчин етакридину лактат у концентраціях 0,1; 0,05; 0,01%. Отримані результати дозволяють зробити висновок, що розчин етакридину лактату в концентрації 0,1% підвищує чутливість мікроорганізмів до дії низькоінтенсивного лазерного випромінювання. В ході проведеного експерименту було встановлено антимікробну дію комбінованого впливу 0,1%-вого розчину етакридину лактату і лазерного випромінювання синього спектра, що проявляється зниженням числа КУО/мл сукупної мікрофлори зубного нальоту. Кількість КУО знижується зі значення 14,3±0,12 × 103/мл до значення 2,4±0,3 × 102/мл після опромінення. Зіставляючи дані контролю (початкове число колоній, що виросли) і досліду (число колоній, що виросли після проведення фотоактивованої дезінфекції), ми встановили, що антимікробна дія фотоактивованої дезінфекції знаходиться в прямій залежності від тривалості опромінення. Так, ефективність комбінованого використання фотосенсибілізатора з НІЛВ в 1,2 рази перевищує активність етакридину лактату (час експозиції – 60 с) і в 2,0 рази перевищує антимікробний ефект лазерного випромінювання синього спектра (час експозиції – 120 с)

    Increased 5-hydroxymethylcytosine and decreased 5-methylcytosine are indicators of global epigenetic dysregulation in diffuse intrinsic pontine glioma

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    Introduction Diffuse intrinsic pontine glioma (DIPG) is a malignant pediatric brain tumor associated with dismal outcome. Recent high-throughput molecular studies have shown a high frequency of mutations in histone-encoding genes (H3F3A and HIST1B) and distinctive epigenetic alterations in these tumors. Epigenetic alterations described in DIPG include global DNA hypomethylation. In addition to the generally repressive methylcytosine DNA alteration, 5-hydroxymethylation of cytosine (5hmC) is recognized as an epigenetic mark associated with active chromatin. We hypothesized that in addition to alterations in DNA methylation, that there would be changes in 5hmC. To test this hypothesis, we performed immunohistochemical studies to compare epigenetic alterations in DIPG to extrapontine adult and pediatric glioblastoma (GBM) and normal brain. A total of 124 tumors were scored for histone 3 lysine 27 trimethylation (H3K27me3) and histone 3 lysine 9 trimethylation (H3K9me3) and 104 for 5hmC and 5-methylcytosine (5mC). An H-score was derived by multiplying intensity (0–2) by percentage of positive tumor nuclei (0-100%). Results We identified decreased H3K27me3 in the DIPG cohort compared to pediatric GBM (p \u3c 0.01), adult GBM (p \u3c 0.0001) and normal brain (p \u3c 0.0001). H3K9me3 was not significantly different between tumor types. Global DNA methylation as measured by 5mC levels were significantly lower in DIPG compared to pediatric GBM (p \u3c 0.001), adult GBM (p \u3c 0.01), and normal brain (p \u3c 0.01). Conversely, 5hmC levels were significantly higher in DIPG compared to pediatric GBM (p \u3c 0.0001) and adult GBM (p \u3c 0.0001). Additionally, in an independent set of DIPG tumor samples, TET1 andTET3 mRNAs were found to be overexpressed relative to matched normal brain. Conclusions Our findings extend the immunohistochemical study of epigenetic alterations in archival tissue to DIPG specimens. Low H3K27me3, decreased 5mC and increased 5hmC are characteristic of DIPG in comparison with extrapontine GBM. In DIPG, the relative imbalance of 5mC compared to 5hmC may represent an opportunity for therapeutic intervention

    Peripheral blood marker of residual acute leukemia after hematopoietic cell transplantation using multi-plex digital droplet PCR

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    BACKGROUND Relapse remains the primary cause of death after hematopoietic cell transplantation (HCT) for acute leukemia. The ability to identify minimal/measurable residual disease (MRD) via the blood could identify patients earlier when immunologic interventions may be more successful. We evaluated a new test that could quantify blood tumor mRNA as leukemia MRD surveillance using droplet digital PCR (ddPCR). METHODS The multiplex ddPCR assay was developed using tumor cell lines positive for the tumor associated antigens (TAA: WT1, PRAME, BIRC5), with homeostatic ABL1. On IRB-approved protocols, RNA was isolated from mononuclear cells from acute leukemia patients after HCT (n = 31 subjects; n = 91 specimens) and healthy donors (n = 20). ddPCR simultaneously quantitated mRNA expression of WT1, PRAME, BIRC5, and ABL1 and the TAA/ABL1 blood ratio was measured in patients with and without active leukemia after HCT. RESULTS Tumor cell lines confirmed quantitation of TAAs. In patients with active acute leukemia after HCT (MRD+ or relapse; n=19), the blood levels of WT1/ABL1, PRAME/ABL1, and BIRC5/ABL1 exceeded healthy donors (p<0.0001, p=0.0286, and p=0.0064 respectively). Active disease status was associated with TAA positivity (1+ TAA vs 0 TAA) with an odds ratio=10.67, (p=0.0070, 95% confidence interval 1.91 - 59.62). The area under the curve is 0.7544. Changes in ddPCR correlated with disease response captured on standard of care tests, accurately denoting positive or negative disease burden in 15/16 (95%). Of patients with MRD+ or relapsed leukemia after HCT, 84% were positive for at least one TAA/ABL1 in the peripheral blood. In summary, we have developed a new method for blood MRD monitoring of leukemia after HCT and present preliminary data that the TAA/ABL1 ratio may may serve as a novel surrogate biomarker for relapse of acute leukemia after HCT

    Splicing is an alternate oncogenic pathway activation mechanism in glioma

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    High-grade diffuse glioma (HGG) is the leading cause of brain tumour death. While the genetic drivers of HGG have been well described, targeting these has thus far had little impact on survival suggesting other mechanisms are at play. Here we interrogate the alternative splicing landscape of pediatric and adult HGG through multi-omic analyses, uncovering an increased splicing burden compared with normal brain. The rate of recurrent alternative splicing in cancer drivers exceeds their mutation rate, a pattern that is recapitulated in pan-cancer analyses, and is associated with worse prognosis in HGG. We investigate potential oncogenicity by interrogating cancer pathways affected by alternative splicing in HGG; spliced cancer drivers include members of the RAS/MAPK pathway. RAS suppressor neurofibromin 1 is differentially spliced to a less active isoform in >80% of HGG downstream from REST upregulation, activating the RAS/MAPK pathway and reducing glioblastoma patient survival. Overall, our results identify non-mutagenic mechanisms by which cancers activate oncogenic pathways which need to accounted for in personalized medicine approaches
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