Antegrade colonic enemas

Thirteen children aged 6-14 (mean 8) years in whom an antegrade colonic enema procedure was performed were reviewed retrospectively. All presented with refractory constipation or faecal soiling over a 3-year period. Nine of the children had previously undergone pull-through procedures for Hirschsprung's disease or high anorectal malformations. Two were suffering from spina bifida and two from idiopathic functional constipation. The operation was performed through a right iliac fossa incision. A catheterizable conduit was created. The appendix was brought out to the wound edge and made continent by intussuscepting the appendix base into the caecum. When the appendix was absent or unusable, a caecal tube was formed. Five patients suffered minor morbidity, six required a further operative procedure and two eventually required a sigmoid colostomy. However, the eventual outcome of a continent stoma was attained in 11 of the 13 children, all of whom would have been considered for sigmoid colostomy before introduction of the antegrade colonic enema procedure.     

Spectral and interferometrical study of the interaction of haemin with glutathione

Neurones in the ureterovesical ganglion complex provide autonomic innervation to the pelvic ureter, the ureterovesical junction and the bladder trigone. We examined the distribution and peptide co-expression pattern of nitric oxide synthase (NOS) in the human ureterovesical ganglia by combining NADPH-diaphorase histochemistry with immunoreactivity for vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), and calcitonin gene-related peptide (CGRP). Less than 20% of nerve cells in the large ganglia of the ureterovesical complex were stained for NOS activity. In elderly individuals, ganglion cells regularly exhibited conspicuous morphological alterations suggestive of degenerative changes. Most of the NOS-positive cell bodies costained for VIP-immunoreactivity. A minority of NOS-expressing cells also reacted for NPY-immunoreactivity. CGRP-immunoreactivity was present in varicose terminal-like nerve fibres which were found to encircle NOS-containing perikarya. Occasionally, NOS-positive somata were surrounded by plexiform axon terminals which immunostained for VIP or NPY. We conclude that the passage of urine across the ureterovesical junction is under relaxatory control of a local nitric oxide/VIP(NPY) pathway which may be modulated by preganglionic efferent and/or primary afferent input.     

Retinal cholinergic system: characterization of rat retinal acetyltransferases using specific inhibitors of choline- and carnitine-acetyltransferases

Choline acetyltransferase catalyzes the synthesis of acetylcholine from choline and acetylcoenzyme A (ACoA) in both nervous and non-nervous tissues. Carnitine acetyltransferase occurs in several tissues and transfers acetyl groups from ACoA to carnitine forming acetylcarnitine and exhibits weak choline acetyltransferase activity. Several haloacetylcholines and haloacetylcarnitines were synthesized to develop selective inhibitors of choline acetyltransferase and carnitine acetyltransferase. Acetylcholine is a transmitter for some presynaptic neurons and/or amacrine cells in retina. Selective inhibitors of choline acetyltransferase and carnitine acetyltransferase were used in the evaluation of choline acetyltransferase and carnitine acetyltransferase activities in the rat retina. Choline acetyltransferase and carnitine acetyltransferase activities were assayed by transferring of [14C]acetyl group from [14C]ACoA to choline or carnitine and estimating [14C]-acetylcholine or [14C]acetylcarnitine. This study gave the following results: (a) Bromoacetylcholine (BrACh) was a selective inhibitor of purified choline acetyltransferase (I50, 2.2 microM); (b) (R)-bromoacetylcarnitine [(R)-BrACa] was more potent for inhibiting purified carnitine acetyltransferase (I50, 4 microM) than purified choline acetyltransferase (I50, 46 microM); (c) Rat retinal sonicate gave choline acetyltransferase activity of 98 +/- 6 nmol of ACh formed/mg/10 min. When the carnitine acetyltransferase was completely inhibited by (R)-BrACa, the activity for choline acetyltransferase decreased to 47 +/- 1 nmol, and this decrease was possibly due to the formation of some [14C]acetylcholine by carnitine acetyltransferase. The net retinal choline acetyltransferase activity was 51 nmol acetylcholine/mg protein/10 min; (d) Rat retinal sonicate contained carnitine acetyltransferase activity of 102 +/- 7 nmol acetylcarnitine formed/mg protein/10 min. This was not altered by inhibition of choline acetyltransferase with BrACh. This means that choline acetyltransferase did not use carnitine as a substrate. Choline acetyltransferase and carnitine acetyltransferase activities did not change after dialysis of retinal sonicates at 4 degrees C for 24 hrs. These observations suggest that BrACh and (R)-BrACa are useful for assessing the correct values for choline acetyltransferase and carnitine acetyltransferase activities in retinal tissues.     

Hochgenaue Abstandsmessung mit Mikrowellen

Using microwave technology for industrial sensing applications has the advantage of being insensitive to environmental influences. The presented near range radar has an accuracy of 0.1 mm. This high precision was achieved by using dynamic frequency divider chips for direct frequency measurement and a six-port for phase measurement at 35 GHz. A digital signal processor calculates the distance.     

Vergleich, Dimensionierung und Realisierung einphasiger Power Factor Correctors minimalen Realisierungsaufwands

In the future laws and restrictions will limit the amplitudes of the low frequency harmonics of mains currents of rectifier systems. While diode bridges are very simple, compact and cheap, their input current shows high low-order harmonics. In the past various rectifier systems have been developed that avoid low-order input current harmonics by means of active current control. The significantly reduced input filter results in a small and compact total rectifier system. In this paper different rectifier systems are discussed and compared. Since industry is interested in simple and cheap solutions the rectifier systems are discussed under these considerations. Besides an introduction of different power circuits and control schemes, the systematic choice of the power semiconductors is presented.