L-arginine effects on myocardial stress in cardiac surgery: preliminary results.

BACKGROUND: L-arginine in addition to cardioplegia stimulates the release of nitric oxide and increases coronary blood flow, decreasing platelet activation and leukocyte adhesion. The aim of our study was to determine the feasibility and the efficacy of the addition of L-arginine to antegrade and retrograde blood cardioplegia in reducing myocardial damage and stress. METHODS: Twenty-eight consecutive patients who underwent coronary artery bypass grafting were randomized to receive 7.5 g of L-arginine in 500 ml of cardioplegic solution. To assess safety of use of L-arginine, hemodynamic evaluation was performed before sternum opening, at sternum closure, and 1 hour after arrival in the intensive care unit to measure cardiac index, systemic and pulmonary vascular resistances, and pulmonary capillary wedge pressure. Moreover, transesophageal echocardiography was performed to assess myocardial contractility. To determine the effects on myocardial stress, blood samples were taken from the retrograde coronary sinus catheter for lactate, interleukin (IL)-2 receptor, IL-6 and tumor necrosis factor (TNF)-alpha levels. Serum samples (preoperatively, 2, 18 and 42 hours after aortic cross-clamping removal) were also analyzed to measure creatine phosphokinase, creatine kinase-MB mass, cardiac troponin T, platelets, and leukocytes. RESULTS: We found statistical differences for IL-2 receptor, IL-6, TNF-alpha, platelets and leukocytes, in favor of the treated group, and decreasing trends in creatine kinase-MB mass and troponin T levels. CONCLUSIONS: The present study shows the positive effects of the addition of L-arginine to cardioplegia. Reduced IL-2 receptor, IL-6 and TNF-alpha indicate a decrease in myocardial stress. Safety of Larginine is related to lower values of systemic vascular resistances and pulmonary capillary wedge pressure observed in group A postoperatively that could improve the patient's outcome in terms of a reduced need for inotropic support. Moreover, the decrease in platelet and leukocyte count in the treated group might express a reduced no-reflow phenomenon and a better reperfusion, limiting endothelial injury from oxygen radical production.

Extracorporeal membrane oxygenation with a poly-methylpentene oxygenator (Quadrox D). The experience of a single Italian centre in adult patients with refractory cardiogenic shock.

Although microporous polypropylene hollow fiber oxygenators are standard devices used for extracorporeal membrane oxygenation (ECMO), they have limitations such as development of plasma leakage. Poly-methylpentene (PMP) is a new material used for the last generation of oxygenators. We reviewed our experience with a new PMP oxygenator (Quadrox D) and a centrifugal pump (RotaFlow) used to support adult patients with refractory cardiogenic shock. Between January 2000 and April 2007, 25 patients required ECMO for primary or postcardiotomy cardiogenic shock. Eighteen patients were analyzed [mean age 60.2 years; 11 (61%) men; 7 (39%) women]. Nine patients (50%) suffered primary cardiogenic shock. Cardiopulmonary resuscitation was applied in 11 patients (61%) with a mean duration time of 31.5 minutes. Mean ECMO duration time was 7.1 +/- 6.3 days (range, 1-27 days). Intra-aortic balloon pump was used in 13 patients (72.2%) with a mean duration time of 7.7 +/- 5 (range, 2-17 days). Twelve patients (66.7%) survived on ECMO and five patients (27.8%) were discharged. Our results indicate the PMP oxygenator and the centrifugal pump provided acceptable results in terms of surviving on ECMO and discharge. Patients with an initial catastrophic hemodynamic status could benefit by means of a rapid institution of ECMO with PMP oxygenators.

How to improve the teaching of urine microscopy.

BACKGROUND: Urinary microscopy is difficult to teach. This paper describes a 1-day course on urine microscopy, which was based on both theoretical and practical sessions at the microscope, during which real urine samples were examined. METHODS: The course was based on: a) an introductory presentation with slides on the main components of urinary sediments and their clinical correlates; b) examination of fixed urine samples under the guidance of two experts; and c) the use of two microscopes, each equipped with a co-observation device for up to 15 observers. RESULTS: Throughout 2005, four courses were held in four Italian towns. Altogether, there were 97 participants (20-27 per course) from 75 laboratories, all graduates with wide but variable experience in the field. During each course, 17-22 urinary sediment components were shown by both bright-field and phase-contrast microscopy and, when indicated, by polarized light. Tests set before and after the course showed a significant improvement (p<0.01) in the identification of erythrocyte subtypes, epithelial cells, fatty components, various types of casts and drug crystals. A questionnaire conducted with participants by phone several months after the course demonstrated that 51.6% and 32.3% of laboratories have introduced or formally requested phase-contrast and polarized-light microscopy, respectively; 45.2% have changed the terminology for urinary epithelial cells; and 87.1% have identified for the first time urinary sediment components that were not recognized or not considered before the course. CONCLUSIONS: Our course demonstrates that it is possible to improve the teaching of urinary microscopy.

Efficacy of donkey's milk in treating highly problematic cow's milk allergic children: an in vivo and in vitro study.

Successful therapy in cow's milk protein allergy rests on completely eliminating cow's milk proteins from the child's diet: it is thus necessary to provide a replacement food. This prospective study investigated tolerance of donkey's milk in a population of 46 selected children with cow's milk protein allergy, for whom it was not possible to use any cow's milk substitute. Thirty-eight children (82.6%) liked and tolerated donkey's milk at the challenge and for the entire duration of follow-up. Catch-up growth was observed in all subjects with growth deficit during cow's milk proteins challenge. The degree of cross-reactivity of immunoglobulin E (IgE) with donkey's milk proteins was very weak and aspecific. Donkey's milk was found to be a valid alternative to both IgE-mediated and non-IgE-mediated cow's milk proteins allergy, including in terms of palatability and weight-height gain.