Novel PEEK-WC membranes with low plasma protein affinity related to surface free energy parameters.

There has been growing interest in innovative materials with specific physico-chemical properties that provide an improved blood/cell compatibility. In this paper we evaluated the performance of new membranes prepared from a modified polyetheretherketone (PEEK-WC) contacting human plasma proteins. These membranes were prepared by using the phase inversion technique. Membrane wettability and affinity to proteins were evaluated by means of contact angle experiments, roughness measurements, and quantitative UV analysis. The energy parameters of membrane surfaces were determined according to Good, van Oss and Chaudhury's theory. The extent of human albumin, fibrinogen and immunoglobulin G adsorption was related to quantitative expressions of the membrane surface hydrophilicity: the base parameter of surface free energy and the free energy of interfacial interaction. The performance of PEEK-WC membranes was compared to that of commercial membranes, which conventionally are used in biomedical applications. The experimental results showed a reduction of protein adsorption on PEEK-WC membranes with respect to other commercial membranes. The low protein affinity of PEEK-WC membranes is due to the intrinsic physico-chemical characteristics of the polymeric material which makes these membranes interesting for potential use in biomedical applications.

Adhesion and function of rat liver cells adherent to silk fibroin/collagen blend films.

Collagen is often used in bioartificial livers as a biomimetic coating to promote liver cell adhesion and differentiation. Animal proteins are expensive and expose the host to risks of cross-species infection due to contamination with prions. Silk fibroin (SF) is a biocompatible protein produced by Bombyx mori silk worms and possibly an alternative to collagen. We prepared SF-collagen blend films with different SF content adherent to the bottom of standard tissue culture dishes, and characterized their surface morphology by SEM, their wettability and examined them for their capacity to support rat liver cell adhesion and metabolism. Cell metabolism was characterized by estimating the rate at which cells eliminated ammonia and synthesized urea for up to 48h of culture. SF-containing films were smooth, clear and more wettable than collagen. Cells readily adhered, formed junctions and small size aggregates on all films. As many cells adhered on SF as on collagen films. Cell adhesion to high collagen content blend films could not be reliably estimated because cells dwelt in the large cavities in the film. The effect of SF on cell metabolism differed with the investigated metabolic pathway. However, cells on SF-containing films eliminated ammonia and synthesized urea at rates generally comparable to, for urea synthesis at times higher than, that of cells on collagen. These results suggest that silk fibroin is a suitable substratum for liver cell attachment and culture, and a potential alternative to collagen as a biomimetic coating.

["Silent" gastroesophageal reflux and upper airway pathologies in childhood]. / Reflusso gastroesofageo "silente" e patologia delle alte vie respiratorie in età pediatrica.

In children, gastroesophageal reflux (GER) plays an important role in both acute and chronic upper airway disorders including stridor, chronic cough, recurrent upper respiratory infections, obstructive apnea, laryngospasm, and wheezing. Diagnosis may prove difficult unless there is reason to suspect GER and one is aware of the concept of "silent" GER. This paper presents our experience with chronic and/or recurrent respiratory disorders of uncertain origin and without gastrointestinal symptoms in children. Thirty-two pediatric patients with upper respiratory symptoms were evaluated. Out-patient 24-hour intraesophageal pH was monitored and 56% of the patients underwent pharyngo-laryngeal fibroscopy. The patients were divided into two subgroups: Group A (18 patients < 6 months of age) and Group B (14 patients > 6 months). All the patients tested positive for GER with a mean Reflux Index of 21.5. The most common symptoms in Group A were apnea-cianosis and stridor while they were chronic cough for group B. The present study confirms the association between GER and respiratory disease and between GER respiratory-related symptoms and patient age. Emphasis is placed on the importance of otolaryngological diagnostic procedures and 24-hour pH-gastroesophageal monitoring in evaluating patients with respiratory disorders related to silent GER.

[Gastric mucosa changes caused by anti-inflammatory agents in childhood]. / Alterazioni mucosali gastriche da assunzione di farmaci antinfiammatori in età pediatrica.

Nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids are very commonly prescribed. Morbidity and mortality from nonsteroidal anti-inflammatory drugs (NSAID) and steroids continue to be a significant health problem. In this paper are reported: 1) the biological insights into injurious effects of NSAIDs and steroids on mucosal protection and repair; 2) our clinical experience in the diagnosis and the management of children affected by secondary ulcer disease induced by therapeutic doses of NSAIDs and steroids; 3) the guidelines in the prevention of the NSAIDs and steroids-induced gastric damage.

Incorporating nursing diagnoses in the postanesthesia care unit record.

The staff in the PACU at Community Memorial Hospital in Menomonee Falls, WI decided to revise the PACU record using nursing diagnoses. We wanted our new record to reflect our standards of care. We identified three standard nursing diagnoses in our standards and used these as the basis for our new form. The three nursing diagnoses were: potential for ineffective airway clearance, potential for pain, and potential for injury. We also provided an area for nonstandard nursing diagnoses to address individual care if needed. We are currently revising this record after using it for 1 year, and we plan to include one more nursing diagnosis: Potential for fluid imbalance will cover intake and output as well as nausea and vomiting, a common problem in the PACU.