Modified Lundie loops improve apraxia of eyelid opening.

BACKGROUND: Current treatments are unsatisfactory for improving apraxia of eyelid opening, defined as a delay or inability to open closed eyelids voluntarily in the presence of intact motor pathways. METHODS: Improvement in functional health was assessed using the Blepharospasm Disability Scale (BDS) in five consecutive patients with apraxia of eyelid opening treated with wire loops affixed behind ordinary spectacles (Lundie loops) and modified to provide pressure on the brow as a stimulus to keep the eyelids elevated. RESULTS: All five patients showed improvement in BDS scores. The mean percentage of normal activity of the study population improved from 25% to 37.6%. Outdoor activities were not significantly altered with the use of the device. CONCLUSIONS: Modified Lundie loops appear to be helpful in improving the functional health of patients with eyelid apraxia. These results will need to be verified in larger trials.     

Otitis media and CNS complications.

Intracranial complications from otitis media can be quite devastating to the patient if an early diagnosis is not made. Patients may develop meningitis, venous sinus thrombosis or cranial nerve palsies, as well as intracranial abscess. The presenting features in such cases may be subtle and include headache, nausea, vomiting, personality changes and signs of increased intracranial pressure as well as focal neurological deficits. A case of intracranial brain abscess is presented in a patient with a history of chronic otitis media with cholesteatoma. Delay in the diagnosis of intracranial complications of otitis media can lead to improper treatment with increased morbidity and mortality. The etiology and treatment of complications affecting the CNS is discussed.     

c-Cbl negatively regulates platelet activation by glycoprotein VI

Summary.  Background : The adapter protein c-Cbl has emerged as having a potential role in negative regulation of immune receptor signaling. The major platelet-signaling receptor for collagen, glycoprotein VI (GpVI), is associated with the Fc receptor (FcR) γ-chain, and signals through a similar pathway to immune receptors. c-Cbl is tyrosine-phosphorylated in response to stimulation of GpVI, whereas phosphorylation of c-Cbl in thrombin-activated platelets is dependent on fibrinogen binding to the integrin GpIIb/IIIa. Objective : To investigate the role of c-Cbl in platelet signaling. Methods : Murine platelets lacking functional c-Cbl or Src family kinases were analyzed. Results : Phosphorylation of c-Cbl through GpVI is reduced in murine platelets deficient in the Src-family kinases Fyn and Lyn, demonstrating that they lie upstream of c-Cbl phosphorylation. Phosphorylation of several proteins of the GpVI-signaling pathway, including the FcR γ-chain, Syk and phospholipase Cγ2 (PLCγ2), is increased in the absence of c-Cbl. In line with this, aggregation is potentiated in response to the GpVI-specific collagen-related peptide (CRP) after a slight delay. A delay in potentiation is also seen in response to stimulation by thrombin. Conclusions : These observations demonstrate that c-Cbl negatively regulates platelet responses to GpVI agonists and to thrombin, with the latter effect possibly being mediated downstream of GpIIb/IIIa. c-Cbl may play a physiological role in helping to prevent unwanted platelet activation in vivo .     

Ambient light,ophthalmic artery blood flow velocities and retinopathy of prematurity

Exposure to bright light was recently proposed as a possible risk factor for the development of retinopathy of prematurity. A semi-longitudinal Doppler ultrasound study was conducted of ophthalmic artery flow velocities at normal and increased ambient light in 22 preterm infants, at post-menstrual ages from 28 to 37 weeks. The aim of this study was to obtain relationships between ophthalmic artery blood flow velocities at various post-menstrual ages and lighting conditions and the occurrence of retinopathy of prematurity. A gradual increase in average blood flow velocities was seen between 28 and 37 weeks. A stepwise increase in flow velocity was seen in all cases when ambient light was increased from moderate to intense. Five of the 22 infants developed retinopathy. No association could be established between ophthalmic artery flow velocities or light-induced changes in flow velocity and the occurrence of retinopathy.     

Development of a Soil Extraction Procedure for Ecotoxicity Characterization of Energetic Compounds

The acetonitrile–sonication extraction method (US EPA Method 8330) associated with aquatic-based toxicity tests was examined to study the ecotoxicity of energetic substances in soil. Three studies were carried out: (1) toxicological characterization of different energetic substances to select a representative toxicant and to validate the choice of bioassays; (2) choice of an appropriate solvent to transfer acetonitrile extracts to the bioassay incubation media; and (3) optimization of Method 8330 using soil samples spiked with the toxicant. Initial studies indicated that pure 2,4,6-trinitrotoluene (TNT) was toxic toVibrio fischeri[Microtox; IC₅₀(15 min) of 4.2 μM], whereas RDX was less toxic (IC₂₀=181 μM) and HMX was not toxic up to its limit of water solubility (<22 μM). Selected pure TNT metabolites were less toxic than TNT. Similar results were found using the 96-hSelenastrum capricornutumgrowth inhibition test. The toxicity of pure TNT in different solvents (acetonitrile, acetone, and DMSO) and that from Method 8330-extracted TNT-spiked soil samples were compared to TNT dissolved in water. Data indicated that DMSO was the most appropriate solvent to transfer the acetonitrile extracts. A modified Method 8330 may be used in conjunction with bioassays and chemical analyses to examine the ecotoxicity of soils contaminated with energetic substances.     

Investigation of the distribution of cementum-associated lipopolysaccharides in periodontal disease by scanning electron microscope immunohistochemistry

Previous work in our laboratory has suggested that cementum-associated LPS is confined to the surface of affected roots. In order to localize the distribution of cementum-associated LPS more precisely, an immunogold/silver labelling system has been utilized to demonstrate LPS on scanning electron microscope images of scaled, extracted teeth. With this technique, antibody binding to the specimen is detected by electron probe X-ray microanalysis of the bound silver label. Most of the detectable LPS was found to be associated with bacteria and calculus which persisted on the root surface despite the scaling of the specimens. Smaller amounts of bound LPS were also detected on the cuticle and surface cementum layers of the affected root surfaces, but in places where some of the underlying cementum had been removed no LPS was detected. These results cast some doubt on the importance of the removal of cementum-bound endotoxins in the treatment of periodontal disease. From these results it is postulated that the principal therapeutic effect of extensive cementum removal by root planing is that it facilitates the removal of plaque and calculus from resorption lacunae, which were a prominent feature of the affected root surfaces.     

Minimal contraction for tissue‐engineered skin substitutes when matured at the air–liquid interface

The structural stability of skin substitutes is critical to avoid aesthetic and functional problems after grafting, such as contractures and hypertrophic scars. The present study was designed to assess the production steps having an influence on the contractile behaviour of the tissue‐engineered skin made by the self‐assembly approach, where keratinocytes are cultured on tissue‐engineered dermis comprised of fibroblasts and the endogenous extracellular matrix they organized. Thus, different aspects were investigated, such as the assembly method of the engineered dermis (various sizes and anchoring designs) and the impact of epithelial cell differentiation (culture submerged in the medium or at the air–liquid interface). To evaluate the structural stability at the end of the production, the substitutes were detached from their anchorages and deposited on a soft substrate, and contraction was monitored over 1 week. Collected data were analysed using a mathematical model to characterize contraction. We observed that the presence of a differentiated epidermis significantly reduced the amount of contraction experienced by the engineered tissues, independently of the assembly method used for their production. When the epidermis was terminally differentiated, the average contraction was only 24 ± 4% and most of the contraction occurred within the first 12 h following deposition on the substrate. This is 2.2‐fold less compared to when the epidermis was cultured under the submerged condition, or when tissue‐engineered dermis was not overlaid with epithelial cells. This study highlights that the maturation at the air–liquid interface is a critical step in the reconstruction of a tissue‐engineered skin that possesses high structural stability. Copyright © 2012 John Wiley & Sons, Ltd.