A comparative analysis of neurosurgical online education materials to assess patient comprehension

Americans have increasingly utilized the internet as a first-line resource for a variety of information, including healthcare-oriented materials. Therefore, these online resources should be written at a level the average American can understand. Patient education resources specifically written for and available to the public were downloaded from the American Association of Neurological Surgeons website and assessed for their level of readability using the Flesch Reading Ease, Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook Grading, Coleman-Liau Index, and Gunning-Fog Index. A total of 71 subsections from different neurosurgical specialties were reviewed, including Cerebrovascular, Spine and Peripheral Nerves, Neurotrauma and Critical Care, Pain, Pediatric, Stereotactic and Functional, and Tumor material. All neurosurgical subspecialty education material provided on the American Association of Neurological Surgeons website was uniformly written at a level that was too high, as assessed by all modalities. In order to reach a larger patient population, patient education materials on the American Association of Neurological Surgeons website should be revised with the goal of simplifying readability.     

Characterization of the interleukin 3 receptor

A variety of homobifunctional crosslinking agents have been used to gain insight into the nature of the murine interleukin 3 (mIL-3) receptor. When [125I]mIL-3 was cross-linked to receptor sites on the surfaces of intact B6SUtA1 cells with disuccinimidyl suberate (DSS), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed the existence of two radiolabeled species with molecular weights of 140 (p140) and 70 (p70) kd (after subtraction of [125I]mIL-3). The relative intensities of the two bands did not change when the [125I]mIL-3 concentration was varied, confirming Scatchard results which suggested only one affinity class. However, when [125I]mIL-3 was crosslinked to intact cells and then incubated at 37 degrees C, the intensity of p140 decreased relative to p70, suggesting a conversion of p140 to p70. This conversion could be inhibited by sodium azide, methylamine, and bacitracin and could also be prevented by first boiling for 1 min in 2% SDS and 5% 2-mercaptoethanol. The putative protease that carried out this apparent conversion appeared to be associated both with plasma membranes prepared from these cells and also with solubilized receptors. Moreover, when p140, crosslinked with both dithiobis succinimidylpropionate and glutaraldehyde, was purified and reelectrophoresed under reducing conditions, p70 could be generated. N-glycanase digestion of p140 and p70 revealed a similar level of N-linked carbohydrate, which upon closer study appeared to consist of two chains, a 3-kd and an 8-kd moiety. Consistent with this data, we propose that the receptor is a 140-kd glycoprotein that is cleaved to a 70-kd surface protein upon mIL-3 binding and chemical crosslinking.     

Rescue of a foreign gene by Sendai virus.

A simple protocol for the rescue of a synthetic genome into a paramyxovirus has been developed. First, a synthetic Sendai virus-like RNA, containing the antisense coding region of the chloramphenicol acetyltransferase gene replacing the coding region of the Sendai virus genome, was transcribed from a cDNA. When introduced into cells that are infected with Sendai virus, this RNA construct was transcribed, replicated, and packaged into infectious virions. The addition of infected cell extract to the RNA prior to transfection markedly enhanced levels of chloramphenicol acetyltransferase expression and rescue. However, this enhancement is not due to encapsidation of the RNA into nucleocapsids as the RNA remains nuclease-sensitive. Uninfected cell extract also enhances expression and rescue efficiency, implying involvement of a cellular factor(s) with the synthetic viral-like RNA construct that allows for enhanced polymerase recognition. This system should allow for the dissection of the various cis-acting RNA signals within the paramyxovirus genome.     

Mechanism of antithrombin III inhibition of factor VIIa/tissue factor activity on cell surfaces. Comparison with tissue factor pathway inhibitor/factor Xa-induced inhibition of factor VIIa/tissue factor activity

Recent studies have shown that antithrombin III (AT III)/heparin is capable of inhibiting the catalytic activity of factor VIIa bound either to relipidated tissue factor (TF) in suspension or to TF expressed on cell surfaces. We report studies of the mechanism of which by AT III inhibits factor VIIa bound to cell surface TF and compare this inhibitory mechanism with that of tissue factor pathway inhibitor (TFPI)-induced inhibition of factor VIIa/TF. AT III alone and AT III/heparin to a greater extent reduced factor VIIa bound to cell surface TF. Our data show that the decrease in the amount of factor VIIa associated with cell surface TF in the presence of AT III was the result of (1) accelerated dissociation of factor VIIa from cell surface TF after the binding of AT III to factor VIIa/TF complexes and (2) the inability of the resultant free factor VIIa-AT III complexes to bind effectively to a new cell surface TF site. Binding of TFPI/factor Xa to cell surface factor VIIa/TF complexes markedly decreased the dissociation of factor VIIa from the resultant quaternary complex of factor VIIa/TF/TFPI/factor Xa. Addition of high concentrations of factor VIIa could reverse the AT III-induced inhibition of cell surface factor VIIa/TF activity but not TFPI/factor Xa-induced inhibition of factor VIIa/TF activity.     

The Epidemiology of Status Epilepticus in the United States

Objective

To summarize trends in status epilepticus (SE) in the United States by age, race, sex, admission source, disposition, incidence rates, and mortality.

Methods

Data from US National Hospital Discharge Survey were used from 1979 to 2010 to identify discharges with SE and common etiologies and complications of SE using International Classification of Diseases, 9th Revision, Clinical Modifications codes. Temporal trends in the incidence and in-hospital mortality of SE were examined with respect to age, sex, and race.

Results

We identified 760,117 discharges with SE over 32 years. The incidence of SE increased from 3.5 to 12.5/100,000 between 1979 and 2010, without a significant change in in-hospital mortality. Higher incidence, earlier age of onset, and higher mortality were observed among males. Age stratification revealed a “U-shaped” distribution with higher incidence at age <10 years (14.3/100,000) and age >50 years (approaching 28.4/100,000). In-hospital mortality, however, was the lowest (2.6 %) at age <10 years and approached 20.2 % with age ≥80 years. The incidence of SE was higher among blacks (13.7/100,000), compared to whites (6.9/100,000) and other races (7.4/100,000). Mortality, however, was lower among blacks (7.2 %) compared to whites and other races (9.8 and 9.2 %, respectively). Black men had the highest incidence (15.0/100,000), relatively younger age of onset (39.3 years) and the lowest mortality (5.6 %). A net temporal decline in the reported prevalence of epilepsy, central nervous system infections, and traumatic brain injury was noted among SE cohort.

Conclusions

The incidence of SE increased nearly fourfold with relatively unchanged mortality. Gender and racial disparities exist in the incidence of SE, and age is an important predictor of mortality.     

Stimulation of dna synthesis by ascorbate in cultures of articular chondrocytes

The addition of 0.2 mM Na L-ascorbate increased the incorporation of ³H-thymidine by rabbit articular chondrocytes in cell and organ culture. The stimulatory response of explants to ascorbate was potentiated by pretreatment of the cartilage with 0.2% clostridial collagenase (type 1) or trypsin for 15–30 minutes. In explants there was a latent period of 3 to 4 days before increased labeling of the nuclei could be detected. The effect was transient and declined after 8 days of culture. It was more evident in organ cultures of immature (3-month-old) than 2- to 3-year-old rabbits. Age differences were not detected in cell cultures. Explants of adult human articular cartilage were stimulated by ascorbate when the medium was supplemented with 10% fresh human serum but not by fetal bovine serum. The findings indicated that synthesis of DNA by articular chondrocytes in situ is regulated by responsiveness of the cells proper to compounds such as vitamin C, by properties of the extracellular matrix, and by factors in the serum. Ascorbate was cytotoxic at concentrations >0.2 mM in the presence of certain batches of serum and when added to monolayers before the cells attached to the surface of the flask.