Performance of Hepatic Artery Velocity in Evaluation of Causes of Markedly Elevated Liver Tests.
Ultrasound in medicine & biology
Bayonet sign in dysphagia lusoria.
Abdominal radiology (New York)
The utility of hepatic artery velocity in diagnosing patients with acute cholecystitis.
Abdominal radiology (New York)
The purpose of this study was to assess the utility of peak systolic proper hepatic artery velocity (HAV) in differentiating causes of severely elevated liver function tests. HAV, hepatic artery resistive index and portal vein velocity of 41 patients with severely elevated liver function tests were evaluated. In 19 patients (46%), the causes were structural (e.g., cholecystitis, cholangitis), whereas in 22 patients (54%) the causes were non-structural (e.g., rhabdomyolysis, drug-induced liver injury). The average HAV for structural causes was 138 ± 68 cm/s, and for non-structural causes, 65 ± 29 cm/s (p < 0.0001). An HAV >100 cm/s was correlated with structural causes (p?=?0.0001). With respect to diagnostic performance, this threshold was 79% sensitive and 86% specific, with a high positive likelihood ratio (5.8) and low negative likelihood ratio (0.24). The resistive index and portal vein velocity were not statistically different. In patients with severely elevated liver function tests, an HAV >100 cm/s can help distinguish structural from non-structural causes, which may guide management while awaiting definitive laboratory tests.
View details for PubMedID 30143340
Qualitative and Quantitative Gadoxetic Acid-enhanced MR Imaging Helps Subtype Hepatocellular Adenomas
2016; 279 (1): 118-127
To test the diagnostic performance of elevated peak systolic hepatic arterial velocity (HAv) in the diagnosis of acute cholecystitis.229 patients with an ultrasound (US) performed for right upper quadrant (RUQ) pain were retrospectively reviewed. 35 had cholecystectomy within 10 days of ultrasound and were included as test subjects. 47 had normal US and serology and were included as controls. Each test patient US was reviewed for the presence of gallstones, gallbladder distention, sludge, echogenic pericholecystic fat, pericholecystic fluid, gallbladder wall thickening, gallbladder wall hyperemia, and reported sonographic Murphy sign. Demographic, clinical, and hepatic artery parameters at time of original imaging were recorded. Acute cholecystitis at pathology was the primary outcome variable.21 patients had acute cholecystitis and 14 had chronic cholecystitis by pathology. For patients who went to cholecystectomy, HAv ?100 cm/s to diagnose acute cholecystitis was more accurate (69%) than the original radiology report (63%), the presence of gallstones (51%), and sonographic Murphy sign (50%). Statistically significant predictors of acute cholecystitis included HAv ?100 cm/s (p = 0.008), older age (p = 0.012), and elevated WBC (p = 0.002), while gallstones (p = 0.077), hepatic artery resistive index (HARI) (p = 0.199), gallbladder distension (p = 0.252), sludge (p = 0.147), echogenic fat (p = 0.184), pericholecystic fluid (p = 0.357), wall thickening (p = 0.434), hyperemia (p = 0.999), and sonographic Murphy sign (p = 0.765) were not significantly correlated with acute cholecystitis compared to chronic cholecystitis.HAv ?100 cm/s is a useful objective parameter that may improve the performance of US in the diagnosis of acute cholecystitis.
View details for PubMedID 28840272
Effects of vocal fold epithelium removal on vibration in an excised human larynx model
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
2015; 138 (1): EL60-EL64
To determine which clinical variables and gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging features are associated with histologically proved hepatocellular adenoma (HCA) genotypic subtypes.In this institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study, clinical information and MR images of 49 histologically proved HCAs from January 2002 to December 2013 (21 patients; mean age, 39 years; age range, 15-59 years) were retrospectively reviewed by two radiologists. Qualitative and quantitative imaging features, including the signal intensity ratio relative to liver in each phase, were studied. HCA tissues were stained with subtype-specific markers and subclassified by a pathologist. Clinical and imaging data were correlated with pathologic findings and compared by using Fisher exact or t test, with a Bonferroni correction for multiple comparisons.Forty-nine HCAs were subclassified into 14 inflammatory, 20 hepatocyte nuclear factor (HNF)-1?-mutated, one ?-catenin-activated, and 14 unclassified lesions. Intralesional steatosis was exclusively seen in HNF-1?-mutated lesions. Marked hyperintensity on T2-weighted images was seen in 12 of 14 (86%) inflammatory lesions compared with four of 21 (19%) HNF-1?-mutated, seven of 14 (50%) unclassified, and zero of one (0%) ?-catenin-activated lesion. Two large lesions (one ?-catenin-activated and one unclassified) transformed into hepatocellular carcinomas and were the only lesions to enhance with marked heterogeneity. In the hepatobiliary phase, all HCA subtypes were hypoenhancing compared with surrounding liver parenchyma, and they reached their nadir signal intensity by 10 minutes after the administration of contrast material before plateauing. HNF-1?-mutated lesions had the lowest lesion signal intensity ratio of 0.47 ± 0.09, compared with 0.73 ± 0.18 for inflammatory lesions (P = .0004), 0.82 for the ?-catenin-activated lesion, and 0.73 ± 0.06 for the unclassified lesion (P = .00002).In this study, all HCA subtypes were hypoenhancing at Gd-EOB-DTPA-enhanced MR imaging in the hepatobiliary phase and reached their nadir signal intensity at 10 minutes. HNF-1?-mutated lesions could be distinguished from other subtypes by having the lowest lesion signal intensity ratio.
View details for DOI 10.1148/radiol.2015142449
View details for Web of Science ID 000378709700011
View details for PubMedID 26505921
Rituximab: an emerging treatment for recurrent diffuse alveolar hemorrhage in systemic lupus erythematosus
2015; 24 (7): 756-759
This study investigated the impact of selective epithelial injury on phonation in an excised human larynx apparatus. With intact epithelium, the vocal folds exhibited a symmetrical vibration pattern with complete glottal closure during vibration. The epithelium was then enzymatically removed from one, then both vocal folds, which led to left-right asymmetric vibration and a decreased closed quotient. Although the mechanisms underlying these vibratory changes are unclear, these results demonstrate that some component of an intact surface layer may play an important role in achieving normal symmetric vibration and glottal closure.
View details for DOI 10.1121/1.4922765
View details for Web of Science ID 000358929000011
View details for PubMedID 26233062
Microstructure Characterization of a Decellularized Vocal Fold Scaffold for Laryngeal Tissue Engineering
2014; 124 (8): E326-E331
Diffuse alveolar hemorrhage (DAH) is a rare manifestation of systemic lupus erythematosus (SLE) and is associated with high mortality rates. Treatment typically consists of aggressive immunosuppression with pulse-dose steroids, cyclophosphamide, and plasma exchange therapy. Mortality rates remain high despite use of multiple medical therapies. We present a case of recurrent DAH in a 52-year-old female with SLE after a deceased donor renal transplant who was successfully treated with rituximab. Our report highlights the pathophysiologic importance of B-cell-mediated immunosuppression in SLE-associated DAH and suggests that rituximab may represent a viable alternative to cyclophosphamide in the treatment of this disease. We also review eight other reported cases of rituximab use in SLE-associated DAH.
View details for DOI 10.1177/0961203314564235
View details for Web of Science ID 000354558900014
View details for PubMedID 25527066
Pancytopenia secondary to cytomegalovirus reactivation.
BMJ case reports
One potential treatment for vocal fold injury or neoplasia is to replace the entire vocal fold with a tissue-engineered scaffold. This scaffold should ideally have similar mechanical properties and extracellular matrix composition as the native vocal fold. As one approach toward this goal, we decellularized human vocal folds and characterized their mechanical properties and extracellular matrix microstructure.Basic science investigation.Human vocal folds were dissected from the laryngeal framework and treated with sodium dodecyl sulfate (SDS) to remove all cells. Mechanical properties were measured by indentation before and after SDS treatment. The extracellular matrix components of collagen, laminin, elastin, and hyaluronic acid were also characterized before and after decellularization using histology and immunofluorescence.After 4 days of SDS treatment, we obtained a scaffold that retained the original geometry of the vocal fold but was devoid of cells. The elastic modulus of the vocal folds did not change significantly before and after decellularization. Upon qualitative inspection, the decellularized vocal folds retained the original collagen, elastin, and laminin content and orientation but lost the original hyaluronic acid.Vocal folds can be decellularized using SDS without adversely affecting its mechanical stiffness and fibrous extracellular matrix. This preliminary study demonstrates the potential of a decellularized scaffold to serve as a tissue-engineered construct for vocal fold replacement.
View details for DOI 10.1002/lary.24605
View details for Web of Science ID 000339482100005
View details for PubMedID 24448829
Stiffness Gradients Mimicking In Vivo Tissue Variation Regulate Mesenchymal Stem Cell Fate
2011; 6 (1)
A 64-year-old woman with a 1-year history of microscopic polyangiitis developed isolated pancytopenia secondary to cytomegalovirus (CMV) reactivation. The patient was originally admitted to the medical service for the management of a rapidly progressing 10 cm ulcer on her left lower extremity. Prior to admission, the patient had been on several immunosuppressive agents for the treatment of microscopic polyangiitis, including prednisone, azathioprine, cyclophosphamide and rituximab. Her hospital course was notable for pancytopenia and after a very thorough diagnostic work-up, the aetiology was found to be secondary to CMV reactivation. This was confirmed by blood analysis that revealed a highly elevated CMV level at 899 100 copies/mL by quantitative PCR. The patient was promptly treated with intravenous ganciclovir for a total course of 14 days before transitioning to an oral regimen. She had a pronounced response to the anti-CMV therapy with complete recovery of her white cell count, haemoglobin and platelet count to baseline.
View details for DOI 10.1136/bcr-2013-201857
View details for PubMedID 24419641
Preparation of hydrogel substrates with tunable mechanical properties.
Current protocols in cell biology
2010; Chapter 10: Unit 10 16-?
Mesenchymal stem cell (MSC) differentiation is regulated in part by tissue stiffness, yet MSCs can often encounter stiffness gradients within tissues caused by pathological, e.g., myocardial infarction ?8.7±1.5 kPa/mm, or normal tissue variation, e.g., myocardium ?0.6±0.9 kPa/mm; since migration predominantly occurs through physiological rather than pathological gradients, it is not clear whether MSC differentiate or migrate first. MSCs cultured up to 21 days on a hydrogel containing a physiological gradient of 1.0±0.1 kPa/mm undergo directed migration, or durotaxis, up stiffness gradients rather than remain stationary. Temporal assessment of morphology and differentiation markers indicates that MSCs migrate to stiffer matrix and then differentiate into a more contractile myogenic phenotype. In those cells migrating from soft to stiff regions however, phenotype is not completely determined by the stiff hydrogel as some cells retain expression of a neural marker. These data may indicate that stiffness variation, not just stiffness alone, can be an important regulator of MSC behavior.
View details for DOI 10.1371/journal.pone.0015978
View details for Web of Science ID 000286511200030
View details for PubMedID 21246050
The modulus of elasticity of the extracellular matrix (ECM), often referred to in a biological context as "stiffness," naturally varies within the body, e.g., hard bones and soft tissue. Moreover, it has been found to have a profound effect on the behavior of anchorage-dependent cells. The fabrication of matrix substrates with a defined modulus of elasticity can be a useful technique to study the interactions of cells with their biophysical microenvironment. Matrix substrates composed of polyacrylamide hydrogels have an easily quantifiable elasticity that can be changed by adjusting the relative concentrations of its monomer, acrylamide, and cross-linker, bis-acrylamide. In this unit, we detail a protocol for the fabrication of statically compliant and radial-gradient polyacrylamide hydrogels, as well as the functionalization of these hydrogels with ECM proteins for cell culture. Included as well are suggestions to optimize this protocol to the choice of cell type or stiffness with a table of relative bis-acrylamide and acrylamide concentrations and expected elasticity after polymerization.
View details for DOI 10.1002/0471143030.cb1016s47
View details for PubMedID 20521229