Controlling selectivity in the Ullmann reaction on Cu(111).

Using a surface science approach, the selectivity in the Ullmann cross-coupling of aryl halides on Cu(111) has been understood and controlled. The binding strength of the reactants and repulsion between them dictates which organometallic intermediates form, and hence the product distribution. Cross coupling can be maximized at low reactant concentrations.

Fungal brain abscesses in neonates: Sonographic appearances and corresponding histopathologic findings.

Extremely preterm neonates and neonates with predisposing conditions such as congenital or acquired immunodeficiency are at high risk for systemic fungal infection. Abscess formation in the brain is a severe complication that occurs in 70% of neonates with systemic fungal infection. Cerebral sonography can be used to diagnose abscesses in the brain in these patients. We report 2 sonographic presentations of fungal brain abscesses in neonates confirmed by postmortem histopathologic examination. The first patient, an extremely preterm neonate of 23 weeks' gestation with a systemic Candida albicans infection, had multiple small, round, hypoechoic lesions with echogenic rims in both brain hemispheres. The second patient, a term neonate with disseminated aspergillosis and DiGeorge syndrome, had a few large echogenic areas in the right periventricular region. Brain imaging should be considered in the diagnostic workup in neonates with suspected systemic fungal infection. Cerebral involvement can be diagnosed at the bedside with cerebral sonography.

Leukocyte and endothelial activation in a laboratory model of extracorporeal membrane oxygenation (ECMO).

An inflammatory response and a capillary leak syndrome frequently develop during the treatment of neonatal respiratory failure by extracorporeal membrane oxygenation (ECMO). The present study was performed to investigate leukocyte activation and endothelial cell dysfunction that are associated with prolonged contact of blood components with synthetic surfaces. Laboratory ECMO was performed with fresh human blood at 37 degrees C for 8 h (n = 6). Leukocyte activation was measured by L-selectin (CD62L) and CD18 integrin surface expression and by neutrophil-derived elastase release. To monitor endothelial activation, endothelial cell ICAM-1 (CD54) expression was measured in cultured endothelial cells from human umbilical veins (HUVEC) after incubation with plasma from the ECMO experiments. CD18 integrin expression was found significantly up-regulated on polymorphonuclear neutrophils and monocytes after 2-4 h of laboratory ECMO. L-selectin was reduced on both cell types during the total duration of the experiments. Soluble L-selectin (sCD62L) and total and differential leukocyte counts remained unchanged during the experiment. Neutrophil-derived elastase content was maximal after 8 h of ECMO. Plasma from the ECMO experiments did not induce ICAM-1 expression of cultured HUVEC. We conclude that prolonged contact with synthetic surfaces during ECMO activates phagocytes, which may contribute to the inflammatory response seen in ECMO-treated patients. Activated phagocytes do not accumulate in the extracorporeal system nor release humoral factors inducing ICAM-1 expression on endothelial cells.

Postnatal changes of extracellular volume, atrial natriuretic factor, and diuresis in a randomized controlled trial of high-frequency oscillatory ventilation versus intermittent positive-pressure ventilation in premature infants <30 weeks gestation.

OBJECTIVES: High-frequency oscillatory ventilation (HFOV) with a high lung volume strategy is an experimental mode of ventilating preterm infants aimed at achieving maximal alveolar recruitment Higher mean airway pressures are used during HFOV than during intermittent positive-pressure ventilation (IPPV), and the intrathoracic volume increase is relatively constant. Both factors increase the risk to depress organ blood flow and diuresis. Our objective was to test the hypothesis that high lung volume HFOV attenuates the postnatal reduction of extracellular volume in preterm infants by reducing plasma atrial natriuretic factor and diuresis. DESIGN: Prospective, randomized, controlled clinical trial. SETTING: University hospital, Level III neonatal intensive care unit. PATIENTS: Premature infants <30 wks gestation requiring intubation for respiratory distress syndrome within the first 6 hrs of life; 15 infants (gestational age, 26 [24-29] wks, birth weight 814 [452-1340] g) were randomized to HFOV, 19 infants (gestational age 27 [24-39] wks, birth weight 930 [644-1490] g) to IPPV. INTERVENTIONS: The randomized mode of ventilation was assigned within 1 hr after intubation. During HFOV mean airway pressure was increased as long as oxygenation improved and no lung overinflation was seen on chest radiograph. IPPV rates were > or =60/min. MEASUREMENTS AND MAIN RESULTS: We measured extracellular volume (sucrose dilution) and atrial natriuretic factor on Day 1 and Day 3. Mean airway pressure, body weight, diuresis, and fluid intake were measured daily. During HFOV mean airway pressure was higher at 12 hrs (median 7 cm H2O vs. 4 cm H2O; p = .001) and 24 hrs (median 6 cm H2O vs. 3 cm H2O; p = .01). In both groups, extracellular volume decreased between Day 1 and Day 3 (HFOV from 428 +/- 126 mL to 344 +/- 145 mL [p = .003], IPPV from 466 +/- 108 mL to 414 +/- 124 mL [p = .01]) and diuresis increased (HFOV, from 2.5 +/- 1.7 to 4.6 +/- 0.9 mL/kg/hr [p = .001]; IPPV, from 2.8 +/- 1.6 to 4.2 +/- 1.0 mL/kg/hr [p = .01]). Plasma atrial natriuretic factor was not decreased in the HFOV group. CONCLUSIONS: High lung volume HFOV as primary mode of ventilation in preterm infants <30 wks gestation did not result in unwanted fluid retention and a decrease in diuresis in the first days of life.

Glial fibrillary acidic protein and RNA expression in adult rat hippocampus following low-level lead exposure during development.

The astroglial cytoskeletal element, glial fibrillary acidic protein (GFAP), is a generally accepted sensitive indicator for neurotoxic effects in the mature brain. We used GFAP as a marker for structural changes in rat hippocampus related to chronic low level lead exposure during different developmental periods. Four groups of rats were investigated: a control group, a perinatal group, which was exposed during brain development (E0-P16), a permanent group, exposed during and after brain development (E0-P100), and a postweaning group, exposed after brain development (P16-P100). Sections were processed for light microscopy (hematoxylin-eosin, Nissl, periodic acid Schiff (PAS) and GFAP-specific immunohistology), for electron microscopy, and for in-situ hybridization (GFAP). Sections were prepared from animals tested for active avoidance learning (AAL) and long-term potentiation (LTP). Chronic lead exposure did not affect glial and neuronal functions, as assessed by LTP and AAL, when lead exposure started after brain development (postweaning group). In this group, astrocytes displayed increased GFAP and GFAP gene transcript levels. However, lead exposure affected neuronal and glial function when the intoxication fell into the developmental period of the brain (perinatal and permanent groups). In these groups, LTP and AAL were impaired, and astrocytes failed to react to the toxic exposure with an adequate increase of GFAP and GFAP gene transcripts. Although GFAP is an accepted marker for neurotoxicity, our data suggest the marker function of GFAP to be restricted to postnatal toxic insult.

[Prosthetic treatment by fixed dentures as an aspect of dental caries prophylaxis and periodontal diseases]. / Leczenie protetyczne protezami stalymi w aspekcie profilaktyki próchnicy i chorob przyzebia.

The application of the new, more rational clinical and laboratory management methods of the fixed dentures performance in the Prosthetics Department in Gdansk is the aim of the paper. The methods and materials take dental caries prophylaxis and parodontium protection into consideration and they are based on: grinding limiting and application of partial crowns for installation instead of normal cost crowns; in the partial crowns there were used such composite materials as: Evicrol, Izopast, Izosit and others. Recently ABC preparation (Adhesive-Bridge-Cement) has also been used. The range of the partial crowns described application is various; they are applied not only in the anterior segments but also in the lateral parts of the dental arch. Wearing fixed dentures together with abiding by the hygienic regime is the common element of all modern, accurate and also careful for the dental tissues and noninvasive for the parodontium methods of treatment by fixed dentures.