21 research outputs found

    Human knee joint finite element model using a two bundle anterior cruciate ligament: Validation and gait analysis

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    Anterior cruciate ligament (ACL) deficient individuals are at a much higher risk of developing osteoarthritis (OA) compared to those with intact ACLs, likely due to altered biomechanical loading [1]. Research indicates the ACL is comprised of two “bundles”, the anteromedial (AM) and posterolateral (PL) bundles [2]. Although the function of both bundles is to restrain anterior tibial translation (ATT), each bundle has their own distinct range of knee flexion where they are most effective [3]. Articular cartilage contact stress measurements are difficult to measure in vivo. An alternative approach is to use knee joint finite element models (FEMs) to predict soft tissue stresses and strains throughout the knee. Initial and boundary conditions for these FEMs may be determined from knee joint kinematics estimated from motion analysis experiments. However, there is a lack of knee joint FEMs which include both AM and PL bundles to predict changes to articular cartilage contact pressures resulting from ACL injuries. The purpose of this study is to develop and validate a knee joint FEM using both AM and PL bundles and subsequently perform a gait analysis of varying ACL injuries

    Inter-Observer Variation in the Pathologic Identification of Minimal Extrathyroidal Extension in Papillary Thyroid Carcinoma

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    Background: Extrathyroidal extension (ETE) is a significant prognostic factor in papillary thyroid carcinoma (PTC). Minimal extrathyroidal extension (mETE) is characterized by involvement of the sternothyroid muscle or perithyroid soft tissue, and is generally identified by light microscope examination. Patients with mETE, identified pathologically, are automatically upstaged to pT3. However, the prognostic implications of mETE have been a source of controversy in the literature. Moreover, there is also controversy surrounding the identification of mETE on pathological specimens. The objective of this study was to determine the level of agreement among expert pathologists in the identification of mETE in PTC cases. Methods: Eleven expert pathologists from the United States, Italy, and Canada were asked to perform a review of 69 scanned slides of representative permanent sections of PTC specimens. Each slide was evaluated for the presence of mETE. The pathologists were also asked to list the criteria they use to identify mETE. Results: The overall strength of agreement for identifying mETE was slight (??=?0.14). Inter-pathologist agreement was best for perithyroidal skeletal muscle involvement (??=?0.46, moderate agreement) and worst for invasion around thick-walled vascular structures (??=?0.02, slight agreement). In addition, there was disagreement over the constellation of histologic features that are diagnostic for mETE, which affected overall agreement for diagnosing mETE. Conclusions: Overall agreement for the identification of mETE is poor. Disagreement is a result of both variation in individual pathologists' interpretations of specimens and disagreement on the histologic criteria for mETE. Thus, the utility of mETE in staging and treatment of PTC is brought into question. The lack of concordance may explain the apparent lack of agreement regarding the prognostic significance of this pathologic feature.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140271/1/thy.2015.0508.pd

    Inter-Observer Variation in the Pathologic Identification of Extranodal Extension in Nodal Metastasis from Papillary Thyroid Carcinoma

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    Background: Extranodal extension (ENE) in lymph node metastases has been shown to worsen the prognosis of papillary thyroid cancer (PTC). Despite the clinical significance of ENE, there are no stringent criteria for its microscopic diagnosis, and its identification is subject to inter-observer variability. The objective of this study was to determine the level of agreement among expert pathologists in the identification of ENE in PTC cases. Methods: Eleven expert pathologists from the United States, Italy, and Canada were asked to review 61 scanned slides of representative permanent sections of PTC specimens from Mount Sinai Beth Israel Medical Center in New York. Each slide was evaluated for the presence of ENE. The pathologists were also asked to report the criteria they use to identify ENE. Results: The overall strength of agreement in identifying ENE was only fair (??=?0.35), and the proportion of observed agreement was 0.68. The proportions of observed agreement for the identification of perinodal structures (fat, nerve, skeletal, and thick-walled vessel involvement) ranged from 0.61 to 0.997. Conclusions: Overall agreement for the identification of ENE is poor. The lack of agreement results from both variation in pathologists' identification of features and disagreement on the histologic criteria for ENE. This lack of concordance may help explain some of the discordant information regarding prognosis in clinical studies when this feature is identified.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140272/1/thy.2015.0551.pd

    Acute kidney injury in patients treated with immune checkpoint inhibitors

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    Background: Immune checkpoint inhibitor-associated acute kidney injury (ICPi-AKI) has emerged as an important toxicity among patients with cancer. Methods: We collected data on 429 patients with ICPi-AKI and 429 control patients who received ICPis contemporaneously but who did not develop ICPi-AKI from 30 sites in 10 countries. Multivariable logistic regression was used to identify predictors of ICPi-AKI and its recovery. A multivariable Cox model was used to estimate the effect of ICPi rechallenge versus no rechallenge on survival following ICPi-AKI. Results: ICPi-AKI occurred at a median of 16 weeks (IQR 8-32) following ICPi initiation. Lower baseline estimated glomerular filtration rate, proton pump inhibitor (PPI) use, and extrarenal immune-related adverse events (irAEs) were each associated with a higher risk of ICPi-AKI. Acute tubulointerstitial nephritis was the most common lesion on kidney biopsy (125/151 biopsied patients [82.7%]). Renal recovery occurred in 276 patients (64.3%) at a median of 7 weeks (IQR 3-10) following ICPi-AKI. Treatment with corticosteroids within 14 days following ICPi-AKI diagnosis was associated with higher odds of renal recovery (adjusted OR 2.64; 95% CI 1.58 to 4.41). Among patients treated with corticosteroids, early initiation of corticosteroids (within 3 days of ICPi-AKI) was associated with a higher odds of renal recovery compared with later initiation (more than 3 days following ICPi-AKI) (adjusted OR 2.09; 95% CI 1.16 to 3.79). Of 121 patients rechallenged, 20 (16.5%) developed recurrent ICPi-AKI. There was no difference in survival among patients rechallenged versus those not rechallenged following ICPi-AKI. Conclusions: Patients who developed ICPi-AKI were more likely to have impaired renal function at baseline, use a PPI, and have extrarenal irAEs. Two-thirds of patients had renal recovery following ICPi-AKI. Treatment with corticosteroids was associated with improved renal recovery

    Social Transfer of Pathogenic Fungus Promotes Active Immunisation in Ant Colonies

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    Social contact with fungus-exposed ants leads to pathogen transfer to healthy nest-mates, causing low-level infections. These micro-infections promote pathogen-specific immune gene expression and protective immunization of nest-mates

    The IDENTIFY study: the investigation and detection of urological neoplasia in patients referred with suspected urinary tract cancer - a multicentre observational study

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    Objective To evaluate the contemporary prevalence of urinary tract cancer (bladder cancer, upper tract urothelial cancer [UTUC] and renal cancer) in patients referred to secondary care with haematuria, adjusted for established patient risk markers and geographical variation. Patients and Methods This was an international multicentre prospective observational study. We included patients aged ≄16 years, referred to secondary care with suspected urinary tract cancer. Patients with a known or previous urological malignancy were excluded. We estimated the prevalence of bladder cancer, UTUC, renal cancer and prostate cancer; stratified by age, type of haematuria, sex, and smoking. We used a multivariable mixed-effects logistic regression to adjust cancer prevalence for age, type of haematuria, sex, smoking, hospitals, and countries. Results Of the 11 059 patients assessed for eligibility, 10 896 were included from 110 hospitals across 26 countries. The overall adjusted cancer prevalence (n = 2257) was 28.2% (95% confidence interval [CI] 22.3–34.1), bladder cancer (n = 1951) 24.7% (95% CI 19.1–30.2), UTUC (n = 128) 1.14% (95% CI 0.77–1.52), renal cancer (n = 107) 1.05% (95% CI 0.80–1.29), and prostate cancer (n = 124) 1.75% (95% CI 1.32–2.18). The odds ratios for patient risk markers in the model for all cancers were: age 1.04 (95% CI 1.03–1.05; P < 0.001), visible haematuria 3.47 (95% CI 2.90–4.15; P < 0.001), male sex 1.30 (95% CI 1.14–1.50; P < 0.001), and smoking 2.70 (95% CI 2.30–3.18; P < 0.001). Conclusions A better understanding of cancer prevalence across an international population is required to inform clinical guidelines. We are the first to report urinary tract cancer prevalence across an international population in patients referred to secondary care, adjusted for patient risk markers and geographical variation. Bladder cancer was the most prevalent disease. Visible haematuria was the strongest predictor for urinary tract cancer

    Congenital sideroblastic anemia due to mutations in the mitochondrial HSP70 homologue <i>HSPA9</i>

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    The congenital sideroblastic anemias (CSAs) are relatively uncommon diseases characterized by defects in mitochondrial heme synthesis, iron-sulfur (Fe-S) cluster biogenesis, or protein synthesis. Here we demonstrate that mutations in HSPA9, a mitochondrial HSP70 homolog located in the chromosome 5q deletion syndrome 5q33 critical deletion interval and involved in mitochondrial Fe-S biogenesis, result in CSA inherited as an autosomal recessive trait. In a fraction of patients with just 1 severe loss-of-function allele, expression of the clinical phenotype is associated with a common coding single nucleotide polymorphism in trans that correlates with reduced messenger RNA expression and results in a pseudodominant pattern of inheritance
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