Volatile Anesthetics Selectively Inhibit the Calcium sup 2+ -transporting ATPase in Neuronal and Erythrocyte Plasma Membranes

Background: The activity of the plasma membrane Calcium2+ - transporting adenosine triphosphatase (PMCA) is inhibited by volatile anesthetics at clinical concentrations. The goal of the current study was to determine whether the inhibition is selective as compared to other adenosine triphosphatases (ATPases) and another group of general anesthetics, barbiturates. In addition, the authors determined whether the response to anesthetics of the enzymes in neuronal membranes is similar to that in erythrocyte membranes.

Methods: The effects of halothane, isoflurane, and sodium pentobarbital on four different ATPase activities were studied at 37 degrees C in two distinct plasma membrane preparations, human red blood cells and synaptosomal membranes from rat cerebellum.

Results: Inhibition patterns of the PMCA by halothane and isoflurane at anesthetic concentrations were very similar in red blood cells and synaptosomal membranes. The half-maximal inhibition (I50) occurred at 0.25-0.30 mM halothane and 0.30-0.32 mM isoflurane. The PMCA in both membranes was significantly more sensitive to the inhibitory action of volatile anesthetics (I50 = 0.75-1.15 minimum alveolar concentration) than were other ATPases, such as the Sodium sup +, Potassium sup + -ATPase (I50 [nearly equal] 3 minimum alveolar concentration) or Magnesium sup 2+ -ATPase (I50 greater or equal to 5 minimum alveolar concentration). In contrast, sodium pentobarbital inhibited the PMCA in both membranes only at [nearly equal] 100-200-fold above its anesthetic concentrations. The other ATPases were inhibited at similar pentobarbital concentrations (I50 = 11-22 mM).     

Recurrent antepartum compression of a single artery double nuchal cord necessitating emergency cesarean delivery

Fetuses with a single umbilical artery are considered at increased risk for chromosomal and structural abnormalities, and increased adverse perinatal outcome. A young nulliparous patient was followed with weekly nonstress testing due to well-controlled gestational diabetes, a single umbilical artery, and a double nuchal cord. At 31 weeks gestation, following the occurrence of a severe prolonged variable deceleration of the fetal heart rate the patient was hospitalized for close fetal surveillance with consideration that the deceleration may represent recurring intermittent compression of the single umbilical artery. Continuous fetal monitoring depicted recurrent severe variable decelerations of the fetal heart rate. Thirty-six hours after admission, prolonged fetal bradycardia to 60 bpm necessitated emergency cesarean delivery of a nonhypoxic nonacidotic fetus, which subsequently did well. This case suggests that fetuses with a single umbilical artery nuchal cord(s) may be at increased risk of significant umbilical cord compression.     

Differentiation of Potato virus Y strains using improved sets of diagnostic PCR-primers

Potato virus Y (PVY) is one of the most important viruses of potato world-wide, several strain groups are recognized. In the past two decades, novel PVY variants have appeared causing necrotic symptoms on potato tubers. Implicated are two groups of recombinant strains: PVY^NW and PVY^NTN, and NA-PVY^NTN. While the first two are recombinants between PVY-N- and O-strains the latter is a recombinant between an N-strain and an unknown PVY strain or other Potyvirus. Available biological and molecular data on PVY suggest that classification of PVY strains has to be revised. Some drawbacks have been found with recently published primers used in RT-PCR based differentiation of PVY strains as some defined isolates could not be identified correctly. Consequently we developed new primers using both recently available sequences and newly generated complete sequences of PVY strains. The reliability of these newly developed primers and procedures was successfully demonstrated on nearly 100 biologically and serologically characterised PVY isolates.     

Acute onset of severe hemolysis, elevated liver enzymes, and low platelet count syndrome in a patient with a partial hydatidiform mole at 17 weeks gestation

Preeclampsia is uncommon prior to 24 weeks gestation and has been associated with partial and complete hydatidiform moles. We present an unusual case in which a patient was diagnosed with preeclampsia at 17 weeks gestation. Ultrasound findings were consistent with a partial hydatidiform mole. Within 24 hours of the onset of symptoms, the patient developed severe hemolysis, elevated liver enzymes, and low platelet count syndrome, with a platelet count of 20 x 10 (9) cells/L. Termination of pregnancy was performed with rapid resolution of signs, symptoms, and laboratory abnormalities. Triploid 69,XXY was confirmed at karyotype analysis. This case demonstrates the acuteness in which life-threatening maternal conditions can arise with this uncommon complication of pregnancy, and the importance of correct identification of the characteristic ultrasonographic findings associated with a partial hydatidiform mole.