COMPARISON OF THE EFFECTS OF ATROPINE AND GLYCOPYRROLATE ON COGNITIVE FUNCTION FOLLOWING GENERAL ANAESTHESIA

Tests of orientation, concentration and shortterm visual memorywere used to assess 72 patients 1 day before, and 2 days after,elective major surgery. Patients were premedicated with papaveretumand either atropine or glycopyrrolate, before receiving a standardgeneral anaesthetic. Those who had received atropine showedsignificant postoperative short-term memory deficit (P< 0.01),but no change in orientation or concentration. Those who hadbeen given glycopyrrolate showed no significant cognitive changesafter surgery. As glycopyrrolate does not cross the blood-brainbarrier freely, these findings support the involvement of centralcholinergic mechanisms in the deterioration of cognitive functionin the postoperative period.     

A case of supravalvular aortic stenosis with spontaneous remission of peripheral pulmonary stenosis

A 14-year-old junior high school boy was admitted to our institute. Previously he had been diagnosed as having peripheral pulmonary stenosis (Gay's classification, type IV) at the age of 2 years and 10 months. On this occasion, however, a diagnosis of supravalvular aortic stenosis was made, with a pressure gradient of about 120 mmHg, and all examinations showed spontaneous remission of peripheral pulmonary stenosis. He underwent a successful standard aortoplasty. This is the first reported case of spontaneous remission of peripheral pulmonary stenosis.     

Cystatin C, alias post-gamma-globulin: a marker for multiple sclerosis?

Cystatin C, alias post-gamma-globulin or gamma-trace protein, has been shown to be a potent inhibitor of cysteine proteinases; this protein is normally present in different biological fluids, but particularly so in cerebrospinal fluid. The concentration of cystatin C was determined by radial immunodiffusion in cerebrospinal fluid from patients affected with multiple sclerosis, patients affected with various neurological diseases and in controls; it was also determined in brain tissue from 2 patients affected with multiple sclerosis and 3 control brains. Cystatin C cerebrospinal fluid levels were undetectable or depressed in many multiple sclerosis cases and the median value differed significantly from the control one. Its low concentration in multiple sclerosis suggests that the regulation of cysteine proteinases is impaired in this disease; hence enhanced activity of cysteine proteinases could initiate, or increase the breakdown of myelin. Although it is perhaps a little premature to consider cystatin C as a marker for multiple sclerosis, this protein is nevertheless associated to demyelination; consequently its biochemical assay in cerebrospinal fluid is recommended as a complementary diagnostic tool.     

Unilateral pseudobulbar syndrome with limited capsulothalamic infarction

A unilateral pseudobulbar syndrome consequent to unilateral capsulothalamic infarction is described. Motor deficit of the face was associated with marked velar and pharyngeal unilateral palsy; paresis of limbs was mild. ACT scan revealed a circumscribed infarction of the genu of the internal capsule. This raised the problem of unilateral supranuclear pharyngeal palsies and of the precise anatomy of the genicular tract in the genu of the internal capsule.     

Posterior ischemic optic neuropathy during general surgery

We examined two patients who awoke with profound bilateral visual loss after operations under general anesthesia. Their fundi, initially normal, later showed bilateral optic atrophy. Neither patient showed other neurologic deficits, although one demonstrated radiologic evidence of a small cerebral infarction in the deep white matter. These patients probably suffered intraoperative infarction of the retrobulbar segments of both optic nerves, producing posterior ischemic optic neuropathy. Profound systemic hypotension may have been a contributing factor in one patient, the use of the pump-oxygenator in the other, and anemia in both.     

Recycling and EH domain proteins at the synapse

In neurons, a network of endocytic proteins accomplishes highly regulated processes such as synaptic vesicle cycling and the timely internalization of intracellular signaling molecules. In this review, we discuss recent advances on molecular networks created through interactions between proteins bearing the Eps15 homology (EH) domain and partner proteins containing the Asn–Pro–Phe (NPF) motif, which participate in important aspects of neuronal function as the synaptic vesicle cycle, the internalization of nerve growth factor (NGF), the determination of neuronal cell fate, the development of synapses and the trafficking of postsynaptic receptors. We discuss novel functional findings on the role of intersectin and synaptojanin and then we focus on the features of an emerging family of EH domain proteins termed EHDs (EH domain proteins), which are important for endocytic recycling of membrane proteins.     

Minimizing macrovessel signal in cerebral perfusion imaging using independent component analysis.

The pronounced susceptibility effect of macrovessels in MR bolus-tracking studies induces spots of artificially high blood flow and volume in perfusion parameter images. These high-intensity regions impede the detection of perfusion changes and lead to elevated perfusion parameters in adjacent tissues. The purpose of this work was to explore postprocessing methods to reduce the influence of macrovessel signal in dynamic MRI. After data reduction was performed with the use of a principal component analysis (PCA), an independent component analysis (ICA) was applied to separate signal components of different compartments. Based on this decomposition, the dynamic time series were reconstructed with minimized contributions of macrovessel signal and noise. The influence of the temporal resolution and signal-to-noise ratio (SNR) of the source data were investigated by means of a simulation study. A region-of-interest (ROI)-based analysis of corrected and uncorrected in vivo data demonstrated that the influence of arteries and veins was reduced at least by 50%, while gray matter (GM) and white matter (WM) tissues were nearly unaffected by the correction process. Hemodynamic parameter images of the cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) were calculated from corrected and uncorrected scans. The corrected parameter images showed a clearly reduced macrovessel signal and an improved perceptibility of microvascular perfusion changes compared to the uncorrected ones.