Astrocytic induction of matrix metalloproteinase-9 and edema in brain hemorrhage.

We tested the hypothesis that astrocytic matrix metalloproteinase-9 (MMP-9) mediates hemorrhagic brain edema. In a clinical case of hemorrhagic stroke, MMP-9 co-localized with astrocytes and neurons in peri-hematoma areas. In a mouse model where blood was injected into striatum, MMP-9 was colocalized with astrocytes surrounding the hemorrhagic lesion. Because MMP-9 is present in blood as well as brain, we compared four groups of wild type (WT) and MMP-9 knockout (KO) mice: WT blood injected into WT brain, KO blood into KO brain, WT blood into KO brain, and KO blood into WT brain. Gel zymography showed that MMP-9 was elevated in WT hemorrhagic brain tissue but absent from KO hemorrhagic brain tissue. Edematous water content was elevated when WT blood was injected into WT brain. However, edema was ameliorated when MMP-9 was absent in either blood or brain or both. To further assess the mechanisms involved in astrocytic induction of MMP-9, we next examined primary mouse astrocyte cultures. Exposure to hemoglobin rapidly upregulated MMP-9 in conditioned media within 1 to 24 h. Hemoglobin-induced MMP-9 was reduced by the free radical scavenger U83836E. Taken together, these data suggest that although there are large amounts of MMP-9 in blood, hemoglobin-induced oxidative stress can trigger MMP-9 in astrocytes and these parenchymal sources of matrix degradation may also be an important factor in the pathogenesis of hemorrhagic brain edema.     

Similarities in Skeletal Muscle Strength and Exercise Capacity Between Renal Transplant and Hemodialysis Patients

Exercise intolerance is common in hemodialysis (HD) and renal transplant (RTx) patients. Aim of the study was to assess to what extent exercise capacity and skeletal muscle strength of RTx patients differ from HD patients and healthy controls and to elucidate potential determinants of exercise capacity in RTx patients. Exercise capacity, muscle strength, lean body mass (LBM) and physical activity level (PAL) were measured by cycle-ergometry, isokinetic dynamometry, DEXA and Baecke Questionnaire, respectively, in 35 RTx, 16 HD and 21 controls. VO2peak and muscle strength of the RTx patients were significantly lower compared to controls (p<0.01), but not different compared to HD patients. In RTx patients, strength (p<0.001), PAL (p=0.001) and age (p=0.045) were significant predictors of VO2peak. Muscle strength was related to LBM (p=0.001) and age (p=0.001), whereas gender (p<0.001) and renal function (p=0.01) turned out to be significant predictors of LBM. No effects of corticosteroids were observed. Exercise capacity and muscle strength seem equally reduced in RTx and HD patients compared to controls. In RTx patients, muscle strength and PAL are highly related to exercise capacity. Renal function appears to be a significant predictor of LBM, and through the LBM, of muscle strength and exercise capacity.     

Heat inactivation of avian influenza and Newcastle disease viruses in egg products.

Avian influenza (AI) and Newcastle disease (ND) viruses are heat labile viruses, but exact parameters for heat inactivation at egg pasteurization temperatures have not been established. In this study we artificially infected four egg products with two AI (one low [LP] and one high pathogenicity [HP]) and three ND (two low and one highly virulent) viruses, and determined inactivation curves at 55, 57, 59, 61 and 63 degrees C. Based on D(t) values, the time to inactivation of the viruses was dependent on virus strain and egg product, and was directly related to virus titre, but inversely related to temperature. For all temperatures, the five viruses had the most rapid and complete inactivation in 10% salt yolk, while the most resistant to inactivation was HPAI virus in dried egg white. This study demonstrated that the LPAI and all ND viruses were inactivated in all egg products when treated using industry standard pasteurization protocols. By contrast, the HPAI virus was inactivated in liquid egg products but not in dried egg whites when using the low-temperature industry pasteurization protocol.     

Family nurse practitioner students utilization of Personal Digital Assistants (PDAs): implications for practice.

Personal Digital Assistants (PDAs) are a readily accessible source of information to aid in the delivery of patient care. A pilot group of five Family Nurse Practitioner students used PDAs to organize data and access information relevant to patient care. Utilization of the PDAs in the clinical setting provided practice guidelines, textbook information and protocols that were readily accessible. The PDA made it possible for students to utilize preexisting knowledge with additional learning resources. The PDAs were purchased with funds provided from a United States Department of Health and Human Services, Health Resources and Services Administration (HRSA) grant.     

Benefits of arthroscopic tuberculoplasty in posterior ankle impingement syndrome

The purpose of this work was to describe the posterior ankle impingement syndrome related to the posterolateral tubercle of the talus bone and to present a retrospective analysis of our results after arthroscopic plasty of the tubercle in 15 ankles with a mean 3-year follow-up. Fifteen cases of posterior ankle impingement (PAI) underwent arthroscopic excision of an impinging bone spur. All the patients (13) were retrospectively evaluated at an average of 36 months after index surgery. There were seven women (bilateral in two of them) and six men. Ten were involved in different kinds of sport and three were professional ballet dancers. Preoperative symptoms included pain localized in the posterior ankle, limitation of motion, weakness and swelling. All patients had failed a course of conservative therapies. Surgery was performed through posterolateral and posteromedial portals as described by van Dijk. After soft tissue debridement, partial resection of the posterolateral process was performed until there was complete plantar flexion without bone impingement. Postoperatively, all patients followed the same rehabilitation protocol. Improvement in their impingement symptoms was recorded in all of them according to AOFAS score. One of them (7%) still had occasional discomfort. The results suggest that arthroscopic bone decompression of the posterolateral tubercle in cases of PAI resistant to non-surgical therapies is an effective treatment.