The lateral approach for open splenectomy

BACKGROUND: Laparoscopic splenectomy (LS) has been used increasingly to treat children with hematologic disorders and has been reported to have advantages over open splenectomy performed through a standard vertical or subcostal incision. The authors perform open splenectomy (OS) through a lateral, muscle-splitting approach, and believe their approach is more reasonable in comparison with LS. METHODS: Thirty-nine consecutive open splenectomies performed between 1991 and 1995 were reviewed retrospectively and compared with recent reports of LS. The series included 24 boys and 15 girls with an average age of 9 years and average weight of 37.5 kg. Indications included immune thrombocytopenic purpura (n = 20), hereditary spherocytosis (n = 18), and sickle cell anemia (n = 1). The operation was performed with the child in the lateral decubitus position through a left upper abdominal muscle-splitting incision (off the 11th rib), sparing the rectus muscle. RESULTS: All 39 cases were completed without intraoperative complications with an average surgical time of 98.0 minutes (range, 30 to 302). The average surgical blood loss was 89 mL (range, 10 to 300). The children started feeding an average of 1.2 days (range, 0 to 4) postoperatively, were on a regular diet at an average of 2.0 days (range, 1 to 6) postoperatively, and had an average length of stay of 2.7 days (range, 1 to 6). There was no mortality or morbidity. CONCLUSIONS: Open lateral splenectomy is performed with shorter surgical times, less blood loss, an excellent cosmetic result, no complications, and a length of stay comparable to any of the published series on laparoscopic splenectomy in children. This approach provides a reasonable basis for comparison with laparoscopic splenectomy.     

Weak combined magnetic field affects basic and morphine-induced rat's EEG

The present study was undertaken to find out, whether weak combined magnetic field (CMF) with intensity comparable to that of the Earth's static magnetic field can influence the EEG activity of the rat's brain at normal (non-treated animals) conditions and after intraperitoneal (i.p.) and intracerebroventricular (i.c.v.) administration of morphine in experimental animals bearing chronically implanted electrodes and cannules. Most of the experiments were performed using CMF containing co-linear static (20.9 microT) and alternating sinusoidal (20.9 microT, 48 Hz) components, i.e., tuned for Ca2+-resonance. The effects of the field were estimated by comparison of the averaged EEG frequency spectra in the range of frequencies between 0.8-23 Hz in experimental and control animals. Statistically significant effects of CMF were observed both in non-treated and morphine-treated rats. However, the most profound effect-the drastic power reduction at most EEG frequencies-appeared in the animals subjected to the i.p.-injection of morphine. These results show that weak CMF can influence the spontaneous electrical brain activity. The data obtained are consistent with the findings of other groups demonstrating that weak magnetic fields may drastically modify the effects of both exogenous and endogenous opioids on different basic functions in vertebrates and invertebrates. Possible mechanisms for the observed effects are discussed.     

Effect of shape, size, and valency of multivalent mannosides on their binding properties to phytohemagglutinins

Clusters of di-, tri-, and tetra-antennary alpha-D-mannopyranosides were synthesized in good yields based on the coupling of amine-bearing mono- or trisaccharide [Man alpha(1 --> 6)[Man alpha(1 --> 3)]Man] haptens to poly-isocyanate or -isothiocyanate tethering cores. The relative binding properties of the resulting multivalent ligands were determined by turbidimetric and solid phase enzyme-linked lectin assays (ELLA) using plant lectins (phytohemagglutinins) Concanavalin A (Con A) and Pisum sativum (pea lectin) having four and two carbohydrate binding sites, respectively. Rapid and efficient cross-linking between tetravalent Con A and mannopyranosylated clusters were measured by a microtiter plate version of turbidimetric analyses. In inhibition of binding of the lectins to yeast mannan, the best tetravalent monosaccharide (30) and trisaccharide (31) inhibitors were shown to be 140 and 1155 times more potent inhibitors than monomeric methyl alpha-D-mannopyranoside against pea lectin and Con A, respectively. Compounds 30 and 31 were thus 35- and 289-fold more potent than the reference monosaccharide based on their hapten contents. As a general observation, the ligands bearing the Man alpha(1 --> 6)[Man alpha(1 --> 3)]Man trimannoside structures were found to be more potent inhibitors for Con A than the ligands having single mannoside residues, whereas pea lectin could not discriminate between the two types of ligands.     

Agonist-receptor-arrestin, an alternative ternary complex with high agonist affinity

The rapid decrease of a response to a persistent stimulus, often termed desensitization, is a widespread biological phenomenon. Signal transduction by numerous G protein-coupled receptors appears to be terminated by a strikingly uniform two-step mechanism, most extensively characterized for the beta2-adrenergic receptor (beta2AR), m2 muscarinic cholinergic receptor (m2 mAChR), and rhodopsin. The model predicts that activated receptor is initially phosphorylated and then tightly binds an arrestin protein that effectively blocks further G protein interaction. Here we report that complexes of beta2AR-arrestin and m2 mAChR-arrestin have a higher affinity for agonists (but not antagonists) than do receptors not complexed with arrestin. The percentage of phosphorylated beta2AR in this high affinity state in the presence of full agonists varied with different arrestins and was enhanced by selective mutations in arrestins. The percentage of high affinity sites also was proportional to the intrinsic activity of an agonist, and the coefficient of proportionality varies for different arrestin proteins. Certain mutant arrestins can form these high affinity complexes with unphosphorylated receptors. Mutations that enhance formation of the agonist-receptor-arrestin complexes should provide useful tools for manipulating both the efficiency of signaling and rate and specificity of receptor internalization.     

Molecular stereopharmacology and the search for stereoselective drugs

Analyzing modern trends in stereopharmacology shows that its theoretical aspects are mainly associated with the studies of the steric parameters of active centers of drug receptors and enzymes by using compounds having a well-established stereostructure. Applied stereopharmacology underlines the vital necessity of selective production and use of drug eutomers and active modifications of polymorphic drugs. The creation of an information computer database of stereostructural parameters of drugs is considered to be basic for further design of new selective drugs.     

Manganese transport through human erythrocyte membranes. An EPR study

Manganese uptake by human erythrocytes was investigated in the concentration range 0.5-20 mM in the suspending solution, by using the EPR technique. S shaped dependencies of manganese influx on manganese doping solution concentration for both fresh and vanadate treated erythrocytes were found, with maximum influx values of 4.1 +/- 1.9 x 10(-10) mol/m2 x s and 2.1 +/- 0.3 x 10(-9) mol/m2 x s, respectively. At low manganese concentrations (< 2 mM) the manganese permeability coefficient increases with increasing the doping concentration, the ions cooperate for achieving a transport event. For high manganese concentration (> 5 mM) the permeability coefficient decreases with increasing the doping concentration, the ions competing for the limited amount of transport system. A similar increase in manganese uptake as in vanadate treated erythrocytes was measured for 'in vitro' aged erythrocytes. These results might suggest that human erythrocytes possess an active transport mechanism by which, they oppose to manganese influx. This hypothesis is also supported by the 10-15 min time lag between the moment of doping and the start of the manganese influx into the fresh erythrocytes. The manganese uptake inhibition by nifedipine, a calcium channel blocker, for the case of vanadate treated erythrocytes, suggests that, at least partially, manganese uptake by the cells occurs via the 'calcium channels'.     

Diagnosis and treatment of leiomyosarcomas of inferior vena cava

3 clinical cases and literature data, illustrate effective diagnostic and surgical policy in patients with uncommon type of tumor. Two patients were previously operated in other clinics, but the operations were diagnostic because the tumors were estimated as being inoperable. In all 3 patients radical operations were carried out with resection of infrarenal segment of inferior cava vein without its prosthetic reconstruction. In did not result in substantial blood flow disturbances, because before the operation it was known about the presence of well functioning collaterals. The significance of ultrasound examination, especially duplex scanning, computer tomography and angiography (cavagraphy) is emphasized. Favourable results of treatment, especially conclusion of the tumor resectability are more common in specialized institutions.     

Chronic fatigue syndrome: physical and cardiovascular deconditioning

We investigated whether chronic fatigue syndrome (CFS) patients have physical and/or cardiovascular de-conditioning, in 273 CFS patients and 72 healthy controls. We used laboratory tests to assess haematological, biochemical, endocrinological and immunological systems. The cardiovascular system was assessed by echocardiography and carotid echography. Body composition was determined by dual energy X-ray absorptiometry (DEXA). CFS patients had smaller left ventricular end systolic (p < 0.001) and diastolic (p = 0.008) dimensions but thinner posterior walls (p = 0.02) than corresponding values in healthy controls. Left ventricular mass was also reduced in CFS patients (p = 0.006). Both maximum (p < 0.001) and minimum (p < 0.008) diameter of the carotid artery were smaller in CFS patients. The laboratory screening tests showed significant differences in serum albumin (p = 0.05), phosphate (p = 0.02), HDL-cholesterol (p = 0.03), HDL:total cholesterol ratio (p = 0.01), triglycerides (p = 0.02), neutrophils (p = 0.01) and thyroid-stimulating hormone (p = 0.04) between CFS patients and controls. Male CFS patients had an increased percentage of fat mass compared with healthy male subjects (p = 0.02). This large group of CFS patients had evidence of physical and cardiovascular de-conditioning, suggesting that in these patients a graded exercise programme could lead to physical reconditioning and could increase their ability to perform physical activities.