Portal hypertension changes following selective splenorenal shunt surgery. Evaluation by percutaneous transhepatic portal catheterization, venography, and cinefluorography

A series of ergot alkaloids, together with the DA agonists apomorphine and piribedil, were tested for protective effects against audiogenic seizures in an inbred strain of mice (DBA/2) and for induction of circling behaviour in mice with unilateral destruction of one nigrostriatal DA pathway. The order of potency against audiogenic seizures was apomorphine greater than ergocornine greater than bromocryptine greater than ergometrine greater than LSD greater than methysergide greater than piribedil while that observed in the rotating mouse model was apomorphine greater than ergometrine greater than ergocornine greater than bromocryptine greater than piribedil. LSD caused only weak circling behaviour even when administered in high doses (greater than 1 mg/kg). Methysergide was ineffective. Prior administration of the neuroleptic agent haloperidol blocked the effect of DA agonists and of ergot alkaloids in both animal models. The possible action of ergot alkaloids as DA agonists is discussed.     

Validation of a new blood-mimicking fluid for use in Doppler flow test objects

PM28A is a major intrinsic protein of the spinach leaf plasma membrane and the major phosphoprotein. Phosphorylation of PM28A is dependent in vivo on the apoplastic water potential and in vitro on submicromolar concentrations of Ca2+. Here, we demonstrate that PM28A is an aquaporin and that its water channel activity is regulated by phosphorylation. Wild-type and mutant forms of PM28A, in which putative phosphorylation sites had been knocked out, were expressed in Xenopus oocytes, and the resulting increase in osmotic water permeability was measured in the presence or absence of an inhibitor of protein kinases (K252a) or of an inhibitor of protein phosphatases (okadaic acid). The results indicate that the water channel activity of PM28A is regulated by phosphorylation of two serine residues, Ser-115 in the first cytoplasmic loop and Ser-274 in the C-terminal region. Labeling of spinach leaves with 32P-orthophosphate and subsequent sequencing of PM28A-derived peptides demonstrated that Ser-274 is phosphorylated in vivo, whereas phosphorylation of Ser-115, a residue conserved among all plant plasma membrane aquaporins, could not be demonstrated. This identifies Ser-274 of PM28A as the amino acid residue being phosphorylated in vivo in response to increasing apoplastic water potential and dephosphorylated in response to decreasing water potential. Taken together, our results suggest an active role for PM28A in maintaining cellular water balance.     

Cloning and characterization of a novel upstream untranslated exon of the mouse Fgf-1 gene

Several recent studies have reported that there is an imbalance of increased oxidant status and decreased antioxidant system in women with preeclampsia and that factor might contribute to the pathogenesis of the disease. The following study examined blood levels of some of the antioxidants (glutathione, glutathione-peroxidase and -SH groups) as markers of lipid peroxidation in women with preeclampsia compared with normal gestation. Blood levels of these antioxidants were found significantly decreased in women with preeclampsia, which allowed us to speculate that there were abnormally increased levels of lipid peroxides. We believe that lipid peroxides are toxic compounds that damage endothelial cells, increase peripheral vasoconstriction and increase thromboxane synthesis and decrease prostacyclin synthesis. We consider that lipid peroxides are not the cause but the effect of oxidative stress induced by ischaemic placenta and leukocytes activation, so the contribute but not induce pathogenesis in preeclampsia.     

A program system interpreting recording of long-latency evoked potentials

An algorithm and a personal computer program for automatic distinguishing between EEC records containing evoked and no potentials, based on the detected invariants reflecting experts' experience in evoked potential analysis have been developed. The efficiency of the programme (its high accuracy and speed, low volume) has been demonstrated in the system for automatic determination of the hearing level by long-latent evoked potentials. It is easily modifiable to identify evoked potentials from other modalities (visual, somatosensory ones) in the systems using the traditional and/or up-to-date computerized EEC equipment.     

Elegant emergency medicine

Spontaneous intracranial hypotension due to a spinal cerebrospinal fluid (CSF) leak is a rare but increasingly recognized cause of postural headaches. The exact cause of these CSF leaks often remains unknown. The authors treated a 32-year-old man with a unique cause of spontaneous intracranial hypotension. He suffered an excruciating headache that was exacerbated by his being in an upright position. The results of four-vessel cerebral angiography were negative; however, magnetic resonance (MR) imaging of the brain revealed pachymeningeal enhancement and hindbrain herniation. A presumptive diagnosis of spontaneous intracranial hypotension was made. Myelography revealed extrathecal contrast material ventral to the cervical spinal cord as well as an unusual midline bone spur at C5-6. The patient's symptoms did not resolve with the application of epidural blood patches, and he subsequently underwent an anterior approach to the C5-6 spur. After discectomy, a slender bone spur that had pierced the thecal sac was found. After its removal, the dural rent was closed using two interrupted prolene sutures. The patient was discharged home 2 days later. On follow up his symptoms had resolved, and on MR imaging the pachymeningeal enhancement had resolved and the cerebellar herniation had improved slightly.