Use of fibronectin and somatomedin-C as markers of enteral nutrition support in traumatized patients using a modified amino acid formula

The purpose of this study was to evaluate the use of serum fibronectin and serum somatomedin-C as nutritional markers during enteral nutrition support (ENS) of critically ill, traumatized patients using an enteral product containing high concentrations of branched-chain amino acids. Twelve critically injured patients received a standard enteral formula with 30 g of a 44% branched-chain amino acid supplement added to each liter of formula. Fibronectin concentration, somatomedin-C concentration, and nitrogen balance were measured on study days 1, 4, 7, 14, 21, 28 or until adequate oral intake began. Both fibronectin and somatomedin-C concentrations increased significantly from baseline by day 7 of ENS. Nitrogen balance increased significantly from baseline by day 4. On days 14 and 21, only somatomedin-C and nitrogen balance increased significantly from baseline. Nitrogen balance was significantly correlated with somatomedin-C concentration (r = 0.53, p less than 0.01), cumulative caloric intake (r = 0.68, p less than 0.01), and cumulative nitrogen intake (r = 0.72, p less than 0.01). The results of this study suggest that serum somatomedin-C is useful and serum fibronectin has potential in monitoring nutrition support response in critically ill, traumatized patients.     

Crosslinking of fibrinogen and fibronectin by free radicals: a possible initial step in adhesion formation in osteoarthritis of the temporomandibular joint.

PURPOSE: Adhesion formation in osteoarthritis (OA) of the temporomandibular joint (TMJ) typically results in a sustained limitation of joint movement. We propose the hypothesis that free-radical-mediated crosslinking of proteins underlies this adhesion formation in affected joints. Free radicals may cause oxidative modification of proteins, creating an opportunity for the formation of intramolecular and intermolecular crosslinks via covalent bonds. This may stabilize protein aggregates, rendering them more resistant to degradation. In this study, the free-radical-mediated crosslinking of model proteins (fibrinogen and fibronectin) was investigated to test our hypothesis that free radicals contribute to adhesion formation via this mechanism in OA of the TMJ. MATERIALS AND METHODS: Physiological clot formation of fibrinogen by thrombin and free-radical-induced crosslinking of fibrinogen and of fibronectin were analyzed using spectrophotometric turbidity measurements, light-scattering techniques, polyacrylamide gel electrophoresis (PAGE), and rotary shadowing. RESULTS: Fibrinogen was shown to aggregate after free radical treatment, as detected using turbidity measurements and light-scattering techniques. Using PAGE, fibrinogen as well as fibronectin was shown to degrade under low oxidative stress. Under high oxidative stress, however, fragments from both proteins were found to be covalently crosslinked, resulting in high-molecular-weight protein aggregates. The aggregation was shown to be at random with rotary shadowing. CONCLUSION: The study shows that high oxidative stress contributes to the formation of crosslinked proteins that may serve as an initial scaffolding for the development of adhesions frequently seen in OA of the TMJ.     

Safety of thrombolysis during cardiopulmonary resuscitation.

The prognosis is generally poor for patients who experience a cardiac arrest. The most common causes of sudden cardiac arrest are massive pulmonary embolism (PE) and acute myocardial infarction (MI). While thrombolysis is a first-line treatment option in massive PE and acute MI, cardiopulmonary resuscitation (CPR) has been regarded as a relative contraindication for thrombolysis because of the anticipated bleeding risk caused by traumatic cardiocompressions. However, an increasing number of case reports and clinical studies on thrombolysis during and after CPR highlight an increased frequency of the return of spontaneous circulation and a better neurological outcome of surviving patients. These effects are mainly due to the thrombolysis of macroscopic blood clots and the amelioration of microcirculatory reperfusion.This article reviews case reports and clinical studies of thrombolysis during and shortly after CPR in order to estimate the risk of severe bleeding events caused by CPR in association with thrombolysis compared with CPR without thrombolysis.Although thrombolysis per se can cause severe and potentially fatal haemorrhage, there is no evidence that severe bleeding events occur more often when thrombolysis is combined with cardiocompressions. In addition, by far the majority of bleeding complications can be treated effectively. Thus, in many cases, the possible benefit of thrombolysis during CPR seems to outweigh the potential risks. However, there may be a publication bias in some case reports and studies towards reporting successful rather than unsuccessful CPRs. In addition, not enough controlled clinical trials have yet been conducted. Therefore, data from large randomised, multicentre studies are needed to definitely answer the question of the relationship between safety and efficacy of this promising treatment option.We conclude that the currently available data do not indicate that thrombolysis contributes to a significant increase in bleeding complications when administered during CPR.     

Penetrating neck injuries: recommendations for selective management

There were 225 patients with penetrating neck wounds admitted over a 4-year period. Mechanism of injury included stab wounds in 59%, gunshot wounds in 32%, and shotgun wounds in 9%. Location of injury was Zone 1, 16%, Zone 2, 42%, Zone 3, 18%, posterior triangle, 12%, and multiple, 12%. The patients were divided into five groups based upon clinical presentation, location of injury and method of management: Group 1 (n = 31) had serious blood loss or respiratory distress and were immediately explored; Group 2 (n = 76) had anterior wounds and equivocal physical findings either without (n = 60) or with negative (n = 16) contrast studies and these had "mandatory explorations"; Group 3 (n = 17) and Group 4 (n = 80) presented the same as Group 2 but Group 3 patients had positive contrast studies and were explored, while contrast studies were negative in Group 4 patients who were observed; Group 5 (n = 21) had posterior injuries and/or presented late with minimal physical findings and they were observed. Positive exploration occurred in 90% of Group 1, 28% of Group 2, and 82% of Group 3. There were no missed injuries in Groups 4 or 5. Two missed esophageal injuries occurred in Group 2, and a missed carotid injury occurred in Group 3. The following guidelines for management have resulted. 1) Unstable patients require immediate exploration. 2) Stable patients with equivocal physical findings can be managed according to results of esophageal examination and angiography. 3) Patients with low probability of injury due to location and clinical presentation can be observed.(ABSTRACT TRUNCATED AT 250 WORDS)