Elucidating Potential Profibrotic Mechanisms of Emerging Biomarkers for Early Prognosis of Hepatic Fibrosis.

Hepatic fibrosis has been associated with a series of pathophysiological processes causing excessive accumulation of extracellular matrix proteins. Several cellular processes and molecular mechanisms have been implicated in the diseased liver that augments fibrogenesis, fibrogenic cytokines and associated liver complications. Liver biopsy remains an essential diagnostic tool for histological evaluation of hepatic fibrosis to establish a prognosis. In addition to being invasive, this methodology presents with several limitations including poor cost-effectiveness, prolonged hospitalizations, and risks of peritoneal bleeding, while the clinical use of this method does not reveal underlying pathogenic mechanisms. Several alternate noninvasive diagnostic strategies have been developed, to determine the extent of hepatic fibrosis, including the use of direct and indirect biomarkers. Immediate diagnosis of hepatic fibrosis by noninvasive means would be more palatable than a biopsy and could assist clinicians in taking early interventions timely, avoiding fatal complications, and improving prognosis. Therefore, we sought to review some common biomarkers of liver fibrosis along with some emerging candidates, including the oxidative stress-mediated biomarkers, epigenetic and genetic markers, exosomes, and miRNAs that needs further evaluation and would have better sensitivity and specificity. We also aim to elucidate the potential role of cardiotonic steroids (CTS) and evaluate the pro-inflammatory and profibrotic effects of CTS in exacerbating hepatic fibrosis. By understanding the underlying pathogenic processes, the efficacy of these biomarkers could allow for early diagnosis and treatment of hepatic fibrosis in chronic liver diseases, once validated.

Automated detection of electroencephalography artifacts in human, rodent and canine subjects using machine learning.

BACKGROUND: Electroencephalography (EEG) invariably contains extra-cranial artifacts that are commonly dealt with based on qualitative and subjective criteria. Failure to account for EEG artifacts compromises data interpretation. NEW METHOD: We have developed a quantitative and automated support vector machine (SVM)-based algorithm to accurately classify artifactual EEG epochs in awake rodent, canine and humans subjects. An embodiment of this method also enables the determination of 'eyes open/closed' states in human subjects. RESULTS: The levels of SVM accuracy for artifact classification in humans, Sprague Dawley rats and beagle dogs were 94.17%, 83.68%, and 85.37%, respectively, whereas 'eyes open/closed' states in humans were labeled with 88.60% accuracy. Each of these results was significantly higher than chance. COMPARISON WITH EXISTING METHODS: Other existing methods, like those dependent on Independent Component Analysis, have not been tested in non-human subjects, and require full EEG montages, instead of only single channels, as this method does. CONCLUSIONS: We conclude that our EEG artifact detection algorithm provides a valid and practical solution to a common problem in the quantitative analysis and assessment of EEG in pre-clinical research settings across evolutionary spectra.

Structure of the NLRP1 caspase recruitment domain suggests potential mechanisms for its association with procaspase-1.

The NLRP1 inflammasome responds to microbial challenges such as Bacillus anthracis infection and is implicated in autoimmune disease such as vitiligo. Human NLRP1 contains both an N-terminal pyrin domain (PYD) and a C-terminal caspase recruitment domain (CARD), with the latter being essential for its association with the downstream effector procaspase-1. Here we report a 2.0 Å crystal structure of the human NLRP1 CARD as a fusion with the maltose-binding protein. The structure reveals the six-helix bundle fold of the NLRP1 CARD, typical of the death domain superfamily. The charge surface of the NLRP1 CARD structure and a procaspase-1 CARD model suggests potential mechanisms for their association through electrostatic attraction.

A BLOC-1 mutation screen reveals a novel BLOC1S3 mutation in Hermansky-Pudlak Syndrome type 8.

Hermansky-Pudlak Syndrome (HPS) is a genetically heterogeneous disorder of lysosome-related organelle biogenesis and is characterized by oculocutaneous albinism and a bleeding diathesis. Over the past decade, we screened 250 patients with HPS-like symptoms for mutations in the genes responsible for HPS subtypes 1-6. We identified 38 individuals with no functional mutations, and therefore, we analyzed all eight genes encoding the biogenesis of lysosome-related organelles complex-1 (BLOC-1) proteins in these individuals. Here, we describe the identification of a novel nonsense mutation in BLOC1S3 (HPS-8) in a 6-yr-old Iranian boy. This mutation caused nonsense-mediated decay of BLOC1S3 mRNA and destabilized the BLOC-1 complex. Our patient's melanocytes showed aberrant localization of TYRP1, with increased plasma membrane trafficking. These findings confirm a common cellular defect for HPS patients with defects in BLOC-1 subunits. We identified only two patients with BLOC-1 defects in our cohort, suggesting that other HPS genes remain to be identified.

Structures of the HIN domain:DNA complexes reveal ligand binding and activation mechanisms of the AIM2 inflammasome and IFI16 receptor.

Recognition of DNA by the innate immune system is central to antiviral and antibacterial defenses, as well as an important contributor to autoimmune diseases involving self DNA. AIM2 (absent in melanoma 2) and IFI16 (interferon-inducible protein 16) have been identified as DNA receptors that induce inflammasome formation and interferon production, respectively. Here we present the crystal structures of their HIN domains in complex with double-stranded (ds) DNA. Non-sequence-specific DNA recognition is accomplished through electrostatic attraction between the positively charged HIN domain residues and the dsDNA sugar-phosphate backbone. An intramolecular complex of the AIM2 Pyrin and HIN domains in an autoinhibited state is liberated by DNA binding, which may facilitate the assembly of inflammasomes along the DNA staircase. These findings provide mechanistic insights into dsDNA as the activation trigger and oligomerization platform for the assembly of large innate signaling complexes such as the inflammasomes.

Homozygosity mapping and whole-exome sequencing to detect SLC45A2 and G6PC3 mutations in a single patient with oculocutaneous albinism and neutropenia.

We evaluated a 32-year-old woman whose oculocutaneous albinism (OCA), bleeding diathesis, neutropenia, and history of recurrent infections prompted consideration of the diagnosis of Hermansky-Pudlak syndrome type 2. This was ruled out because of the presence of platelet δ-granules and absence of AP3B1 mutations. As parental consanguinity suggested an autosomal recessive mode of inheritance, we employed homozygosity mapping, followed by whole-exome sequencing, to identify two candidate disease-causing genes, SLC45A2 and G6PC3. Conventional dideoxy sequencing confirmed pathogenic mutations in SLC45A2, associated with OCA type 4 (OCA-4), and G6PC3, associated with neutropenia. The substantial reduction of SLC45A2 protein in the patient's melanocytes caused the mislocalization of tyrosinase from melanosomes to the plasma membrane and also led to the incorporation of tyrosinase into exosomes and secretion into the culture medium, explaining the hypopigmentation in OCA-4. Our patient's G6PC3 mRNA expression level was also reduced, leading to increased apoptosis of her fibroblasts under endoplasmic reticulum stress. To our knowledge, this report describes the first North American patient with OCA-4, the first culture of human OCA-4 melanocytes, and the use of homozygosity mapping, followed by whole-exome sequencing, to identify disease-causing mutations in multiple genes in a single affected individual.

A BLOC-1 mutation screen reveals that PLDN is mutated in Hermansky-Pudlak Syndrome type 9.

Hermansky-Pudlak Syndrome (HPS) is an autosomal-recessive condition characterized by oculocutaneous albinism and a bleeding diathesis due to absent platelet delta granules. HPS is a genetically heterogeneous disorder of intracellular vesicle biogenesis. We first screened all our patients with HPS-like symptoms for mutations in the genes responsible for HPS-1 through HPS-6 and found no functional mutations in 38 individuals. We then examined all eight genes encoding the biogenesis of lysosome-related organelles complex-1, or BLOC-1, proteins in these individuals. This identified a homozygous nonsense mutation in PLDN in a boy with characteristic features of HPS. PLDN is mutated in the HPS mouse model pallid and encodes the protein pallidin, which interacts with the early endosomal t-SNARE syntaxin-13. We could not detect any full-length pallidin in our patient's cells despite normal mRNA expression of the mutant transcript. We could detect an alternative transcript that would skip the exon that harbored the mutation, but we demonstrate that if this transcript is translated into protein, although it correctly localizes to early endosomes, it does not interact with syntaxin-13. In our patient's melanocytes, the melanogenic protein TYRP1 showed aberrant localization, an increase in plasma-membrane trafficking, and a failure to reach melanosomes, explaining the boy's severe albinism and establishing his diagnosis as HPS-9.

Cardiovascular and electrocardiographic effects of the dopamine receptor agonists ropinirole, apomorphine, and PNU-142774E in conscious beagle dogs.

To confirm recent in vitro findings, we examined the cardiovascular and electrocardiographic (ECG) effects of the dopamine receptor agonists ropinirole, apomorphine, and PNU-142774E in conscious dogs. Intravenous (i.v.) infusions of ropinirole totaling 20 microg/kg maximally reduced mean arterial pressure (MAP; -16 mm Hg) and the ECG PR interval (-13 milliseconds) and increased heart rate (HR; +29 b/min) and QTc length (+33 ms) at a peak plasma drug concentration (p[drug]) of 3.5 ng/ml. I.V. PNU-142774E was better tolerated through 66 microg/kg and a maximal p[drug] of 5.9 ng/ml with negligible cardiovascular changes and mild QTc reduction (13 ms). Apomorphine (25 microg/kg i.v.) was intermediate to ropinirole and PNU-142774E for emesis and peak changes in MAP (-6 mm Hg), HR (+24 b/min), and QTc (+15 milliseconds) at a mean p[drug] of 3.4 ng/ml. By comparison, the class III antiarrhythmic trecetilide (2.0 mg/kg bolus) increased QTc (+58 ms) without affecting mean arterial pressure or heart rate. This study establishes that in conscious dogs, the selective dopamine receptor agonist PNU-142774E has fewer cardiovascular and emetic effects than ropinirole and apomorphine and supports prior in vitro findings that ropinirole and apomorphine but not the PNU-142774E imidazoquinolin analog sumanirole reduces the delayed rectifier current in HERG transfected cells.

Hemi and total TMJ reconstruction using the Christensen prostheses: a retrospective and prospective evaluation.

This chapter further affirms the safety and efficacy of hemi and total temporomandibular joint (TMJ) reconstruction with the Christensen TMJ Prostheses (TMJ Implants, Inc., Golden, CO, USA). Hemi and total TMJ reconstruction with the Christensen TMJ prostheses was first introduced by Robert W. Christensen, DDS in 1961 and 1965, respectively, and is gaining widespread acceptance as a viable alternative in the treatment of temporomandibular joint disorders (TMD). The Christensen TMJ devices have been used to treat various disorders in large numbers of patients, and the pertinent results of 10 years of study are reported in this chapter.

Dermatology and the Americans With Disabilities Act: a review of the case law.

The Americans With Disabilities Act (ADA) defines disability as a physical or mental impairment that substantially limits one or more major life activities. Although dermatology has received relatively little attention in the context of disability law, dermatologic diseases are properly covered by the ADA and are subject to the same criteria as other medical conditions. A Lexis-Nexis search of federal court decisions covering the ADA produced 23 cases dealing with dermatologic impairments as disabilities. In Cehrs v Northeast Ohio Alzheimer Research Center, a federal appeals court held that psoriasis constituted a disability under the Act. Skin diseases not only cause physical and mental impairments, but they are also visible to others. Persons with skin diseases may be "regarded as" disabled, and this can constitute discrimination under the law.

Use of the Christensen TMJ Fossa-Eminence Prosthesis System: a retrospective clinical study.

Disc displacements develop from alterations in the structural integrity of the condyle-disc complex. A definitive treatment that may be considered for such derangements is surgical correction. The goal of surgery is to return the disc to normal functional relationship with the condyle, or replace the disc with an alloplast. Surgery, is, therefore, considered when conservative therapy fails to adequately resolve the symptoms, progression of the disorder occurs, or both.

Periaortic hematoma on abdominal computed tomographic scanning as an indicator of thoracic aortic rupture in blunt trauma.

BACKGROUND: In our institution, we have noted an association between periaortic hematomas (PH) present on abdominal computed tomographic (CT) scans and patients with thoracic aortic rupture (TAR) in blunt trauma. This 5-year retrospective study determined the sensitivity and specificity of PH and left hemothorax seen on abdominal CT scan as an indicator of TAR. METHODS: The trauma registry and records identified 54 blunt trauma patients who had a CT scan of the abdomen and an arch aortogram. Fourteen patients with TAR and 40 patients without TAR were selected for analysis. A digital photograph of an upper cut of the abdominal CT scan for each patient was examined by radiology staff for the presence or absence of PH and left hemothorax. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of PH as a predictor of TAR were 88%, 99%, 97%, and 96%, respectively. CONCLUSION: The finding of PH on CT scan of the abdomen in blunt trauma patients should alert the clinician to the high likelihood of thoracic aortic injury.

On noninvertible mappings of the plane: Eruptions.

In this paper we are concerned with the dynamics of noninvertible transformations of the plane. Three examples are explored and possibly a new bifurcation, or "eruption," is described. A fundamental role is played by the interactions of fixed points and singular curves. Other critical elements in the phase space include periodic points and an invariant line. The dynamics along the invariant line, in two of the examples, reduces to the one-dimensional Newton's method which is conjugate to a degree two rational map. We also determine, computationally, the characteristic exponents for all of the systems. An unexpected coincidence is that the parameter range where the invariant line becomes neutrally stable, as measured by a zero Lyapunov exponent, coincides with the merging of a periodic point with a point on a singular curve. (c) 1996 American Institute of Physics.