The Norwood procedure - does the type of shunt determine outcome?

BACKGROUND: Stage I palliation of hypoplastic left heart syndrome (HLHS) and its variants is usually performed by a Norwood operation. The management of pulmonary blood flow during this procedure remains controversial. The RV-to-PA conduit (RVPAC) has been proposed as the better alternative compared to a systemic-to-pulmonary shunt (SPS). METHODS: A retrospective single center chart review of consecutive patients who underwent a Norwood I procedure between 01/1997 and 09/2006 was performed. All patients were operated in deep hypothermia, with or without circulatory arrest, using different shunt modifications according to surgeon's preference. Patients were divided into two groups depending on surgical management for pulmonary blood flow (modified BT shunt [BT] and non-valved RVPAC [Sano]). RESULTS: Fifty-four patients were included in the study (BT: 31 patients vs. Sano: 23 patients). Diastolic blood pressure during the first 24 hours postoperatively was significantly lower in the BT group (BT: 38.6 +/- 6.9 mmHg vs. Sano: 42.4 +/- 7.2 mmHg; P < 0.01) with a trend towards a higher systolic blood pressure (BT: 74.1 +/- 13.5 mmHg vs. Sano: 69.8 +/- 12.1 mmHg; P = 0.08). Mean circulatory arrest time in the BT group was significantly longer compared to the Sano patients (BT: 41 +/- 21 min vs. Sano: 25 +/- 23 min; P < 0.01). The mean hospital stay was 18.5 days for BT patients and 20 days for Sano patients ( P = 0.45). Early mortality for the total cohort was 14.8 % (n = 8) (BT 19.4 % [n = 6] vs. Sano 8.7 % [n = 2]; P = 0.12). There was no significant difference in inter-stage mortality between the two groups (BT: 18.2 % vs. Sano: 21.1 %; P = 0.47). CONCLUSION: The results for both established surgical methods (BT and Sano) for the palliation of HLHS and its variants have improved over time and are reaching acceptable early mortality rates. There was a trend towards a favorable early outcome for Sano patients, which did not reach statistical significance in this study due to the low patient numbers.

Pharmacokinetics of selenium following oral administration selenium preparation in rabbits.

The aim of study was to investigate the bioavailability of selenium after oral administration of selenium yeast. As a reference preparation was used sodium selenite. The preparations were investigated in rabbits, according to a randomized two way crossover design in the fasted state. Each animal was given selenium preparation in the form of the single oral dose 0.5 mg Se/kg body weight. A washout period of one week separated both treatment periods. The selenium concentration was determined in serum spectrofluorometry. The divalent equation of one-compartment model was the simplest formula describing the course of selenium changes in serum of rabbits and giving the pharmacokinetic parameters. Pharmacokinetic variables (mean maximum plasma concentration, mean time to reach maximum plasma concentration, and the mean area under the plasma concentration-time curve) were not statistically different for the two preparations. It can be concluded that the two selenium preparations are likely to be bioequivalent.

Antioxidant defense in centenarians (a preliminary study).

The study was designed to assess the antioxidant defense mechanisms, either enzymatic or non-enzymatic, in a group of sixteen centenarians (one male and fifteen female subjects aged 101 to 105 years) living in the Upper Silesia district (Poland) in order to evaluate the potential role of antioxidant defenses in human longevity. The results of our preliminary study showed that in comparison with young healthy female adults the centenarians had significantly higher red blood cell glutathione reductase and catalase activities and higher, although insignificantly, serum vitamin E level.

Plasma selenium concentration in patients with stomach and colon cancer in the Upper Silesia.

Plasma selenium concentration was assessed in 44 patients with cancer of the gastrointestinal tract (19 subjects with stomach cancer and 25 with colon cancer) and 25 age-matched healthy control subjects. Selenium concentration was determined by the fluorometric method. The observed plasma selenium concentrations in gastrointestinal cancer patients (37.0 +/- 11.05 ng Se/ml or 38.4 +/- 12.6 ng Se/ml in stomach or colon cancer patients, respectively) were significantly lower as compared to the healthy age-matched control group (51.4 +/- 14.4 ng Se/ml). The diagnosed low selenium status may be considered as a high risk for cancer development.

[A study of erythrocyte oxidative enzyme activity in patients with laryngeal cancer before and after treatment with a selenium preparation CEROSEL]. / Badania zmian aktywnosci enzymów antyoksydacyjnych w krwinkach pacjentów z rakiem krtani przed i po podaniu preparatu selenowego CEROSEL.

The preliminary results of activity changes of antioxidant enzymes (glutathione peroxidase, catalase and superoxide dismutase) in erythrocyte in 19 patients with laryngeal cancer were presented. Enzymes activity in patients was signified three times: before surgery, before and after radiotherapy. During Co-60-therapy patients received leaven preparation of selenium CE-ROSEL in dose 100 micrograms Se/day. Obtained results showed increase of enzymes activity after CE-ROSEL supplementation. This changes are probably the result of selenium influence on protected mechanism before the free radicals.

The action of excessive, inorganic silicon (Si) on the mineral metabolism of calcium (Ca) and magnesium (Mg).

The influence of silicon treatment on the levels of calcium and magnesium in blood serum and tissues was studied in rats. The concentrations of both elements were estimated in samples of sera and tissues of rats receiving per os a soluble, inorganic silicon compound--sodium metasilicate nonahydrate (Na2SiO3.9H2O (REACHIM, USSR)), dissolved in the animals' drinking water. A decrease of magnesium concentration in serum was observed with accompanying elevation of registered calcemia. Moreover, a reduction of tissue calcium levels was found with a simultaneous increase of magnesium tissue pool. The results provide evidence for silicon involvement in mineral metabolism. It could result in a modification of pathological processes concerning bone tissue.

Increase in antioxidant activity in procainamide-treated rats.

Recent studies suggest that in vivo procainamide oxidation underlies induction of autoimmunity by this drug. Since drug metabolism may be accompanied by generation of reactive oxygen species, plasma and liver thiobarbituric acid reacting substances (TBARS), activity of erythrocyte and liver superoxide dismutase, catalase, selenium-dependent glutathione peroxidase (Se-GPX), and plasma antioxidant activity in procainamide treated rats were evaluated. Procainamide administration increased liver lipid peroxide levels, intensified the activity of liver catalase and erythrocyte superoxide dismutase, as well as plasma antioxidant activity. The remaining biochemical parameters in the treated rats were within control values, except for the decreased erythrocyte catalase activity. We conclude, that the increased activity of free radicals observed in the treated rats could contribute to the development of procainamide induced side effects.

Modulation of procainamide toxicity by selenium-enriched yeast in rats.

Free radical processes are proposed to play a crucial role in the development of procainamide adverse effects. Therefore, selenium, as a potent antioxidant, may modified procainamide toxicity. To test this hypothesis plasma and liver thiobarbituric acid-reacting substances (TBARS), plasma antioxidant activity (AOA), erythrocyte and liver superoxide dismutase (SOD), catalase, as well as selenium-dependent glutathione peroxidase (Se-GPX) were determined in the following four groups of rats: selenium-treated (Se), procainamide-treated (P), procainamide and selenium-treated (P + Se), and control (C). Morphological studies of leukocytes [tested for lupus erythematosus (LE) cells] and liver were also made. Atypical, i.e. enlarged and swollen, leukocytes resulting from procainamide and selenium treatment were observed. These changes were found in four out of five rats in the Se group, eight out of ten in the P group, and in seven out of ten in the P + Se group. LE-like cells were observed in two rats in the P + Se group. A statistically significant decrease in plasma and liver TBARS by 20% and 36%, respectively, increased activity of SOD by 20%, catalase by 48% and Se-GPX by 15% in erythrocytes, and decreased activity of liver SOD by 17% and catalase by 22% were found in the P + Se group as compared to the P group. These results indicated that selenium exerted antioxidant effects on the procainamide-treated rats. However, selenium did not prevent the development of disturbances in leukocyte morphology, on the contrary, it possibly promoted the conversion of leukocytes to LE cells.

Silicon metabolism. The interrelations of inorganic silicon (Si) with systemic iron (Fe), Zinc (Zn), and copper (Cu) pools in the rat.

The influence of silicon treatment on the levels of trace elements zinc (Zn), copper (Cu), and iron (Fe) in serum and tissues was studied in rats. The concentrations of silicon, iron, and zinc were estimated in samples of sera and tissues of rats receiving per os a soluble, inorganic silicon compound--sodium metasilicate nonahydrate (Na2SiO3.9H2O), dissolved in the drinking water. An increase of copper concentrations in liver and aortic walls in the experimental group was observed, with simultaneous reduction of zinc amounts in serum and all the tissue samples in the course of the experiment. The iron concentrations in the analyzed samples did not show any significant changes between both groups. The silicon levels in serum and in all the examined tissues were significantly higher in the tested group. The results provide evidence for the silicon interaction with copper and zinc, which could result in a number of metabolic process modifications, antiatheromatous activity among them.