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Biomedical subjects

C Dahlstrand

Publications and source records attributed to C Dahlstrand.

29 records · Page 2Linked to original sources

Transurethral microwave thermotherapy versus transurethral resection for benign prostatic hyperplasia: preliminary results of a randomized study.

The results of transurethral microwave thermotherapy (TUMT) were compared in a prospective randomized study with those of transurethral resection (TURP) in patients with benign prostatic obstruction. In this preliminary report, 39 and 40 patients treated with TUMT and TURP, respectively, were followed between 2 and 12 months. Statistically significant improvements in symptom score, maximum flow rate, residual urine and maximum bladder capacity at cystometry were observed in both groups. The improvements were more pronounced in the TURP group, but major complications were more frequent in this group. Results are compared to other published studies.

Aged↗

Effect of substance P on detrusor muscle in rats with diabetic cystopathy.

Diabetic cystopathy (DCP) is a well known complication in diabetes mellitus (DM). In the present experimental study, DM was induced in rats by streptozotocin and DCP was confirmed on cystometry. In vitro studies on detrusor strips from diabetic rats showed an increased contractile response to substance P (SP) compared with controls, indicating denervation supersensitivity. A decreased response to capsaicin in diabetic detrusor strips indicated a decreased neuronal content of SP or a diminished number of SP-containing sensory nerves. This suggests that DM induces alterations in nerves containing SP which may be at least partly responsible for sensory loss and the development of DCP.

Animals↗

Outpatient-based extracorporeal shock wave lithotripsy using EDAP LT-01.

Between March 1988 and March 1990, 751 patients were treated with shock wave lithotripsy using EDAP LT-01. Six hundred and eight patients had renal stones while 143 patients had stones located in the ureter. Because of difficulties in locating ureteric stones with ultrasound 92% of them were pushed back to the kidney before treatment. The mean stone size was 10 mm, range 4-30 mm. Patients with stones bigger than 15 mm had a double J-stent placed before treatment. The mean number of treatments per patient was 1.7 (range 1-8). Sixty-six per cent of the patients with renal stones were completely stone-free after ESWL monotherapy. Another 5% became stone-free after auxiliary procedures in the ureter, because of retained fragments. Fragments equal to or less than 4 mm were retained in 14% of the patients with the renal stones. Of the patients with ureteric stones mobilised back to the kidney 95% were rendered stone-free after ESWL. Most patients experienced no or very little discomfort during the treatment and only 29% of them received analgesics. General of epidural anaesthesia was given to 1% of the patients. Because of the low demand for analgesia or anaesthesia, 99% of the patients with renal stones were treated on an outpatient basis. During the second year, 74% of the patients with ureteric stones were treated on an outpatient basis.

Adolescent↗

Is the CCK-8 induced relaxation of the feline sphincter of Oddi mediated by VIP neurons?

The regional, intraarterial, injection of CCK-8 elicits reciprocal effects on the motility of the extrahepatic biliary tree in the cat: the contraction of the gallbladder and a relaxation of the sphincter of Oddi as well as of the duodenal wall. After neural blockade with tetrodotoxin the responses of the sphincter to CCK-8 were blocked, and the responses of the gallbladder were markedly reduced. After the regional administration of a VIP antiserum the sphincter relaxation in response to CCK-8 was blocked. Immunocytochemically it was demonstrated that the feline sphincter contains a rich VIP-ergic innervation, while CCK-like immunoreactivity was found only in mucosal endocrine cells. The results indicate that CCK-8 selectively activates inhibitory VIP neurons innervating the sphincter. After the administration of a nonpeptide CCK-receptor antagonist, the CCK-8 induced motor responses of both the sphincter and the gallbladder were markedly reduced. This indicates that blockade of CCK-8 receptors involves muscular as well as neural CCK-receptors.

Animals↗

The vagal nerves and peptides in the control of extrahepatic biliary motility. An experimental study in the cat.

An in vivo model for the simultaneous study of the motility of the gallbladder, sphincter of Oddi and duodenal wall in the anesthetized cat was developed. Changes in gallbladder volume were recorded as well as changes in the outflow from the sphincter of Oddi and from a vein graft inserted through the duodenal wall during perfusion at constant pressure. The distribution of three peptide hormones (substance P-SP, vasoactive intestinal peptide-VIP and cholecystokinin-CCK) within the feline extrahepatic biliary tree was studied immunocytochemically. Nerve terminals with SP-like immunoreactivity (LI) were distributed to the smooth muscle layers and also to acetylcholinesterase-positive ganglions cells in the intrinsic plexa. SP-LI was further demonstrated in cell bodies of the intrinsic plexa as well as in vagal axons. VIP-LI had a similar distribution. An especially rich VIP-ergic innervation was observed within the circular muscle layer of the sphincter of Oddi. SP-LI or VIP-LI did not occur in mucosal endocrine cells. On the other hand, CCK-LI was not demonstrated in nerves but occurred regularly in endocrine cells of the duodenal mucosa. Regional administration of SP elicited dose-dependent contractile motor effects on the biliary tree, which were not dependent on muscarinic or nicotinic cholinoceptors, but were inhibited by infusion of an antagonistic SP analogue indicating a direct effect on the smooth muscle cell. Efferent electrical vagal nerve stimulation elicited contractile motor responses, which were blocked by either atropine or infusion of the SP-analogue, indicating activation of a postganglionic cholinergic neuron via intrinsic or extrinsic SP neurons. These observation correlate well with the presence of SP nerve terminals on acetylcholinesterase-positive ganglion cells of the intrinsic plexa and SP axons within the vagus. An afferent mechanism cannot be excluded; antidromic activation of SP-containing axon collaterals from vagal afferents might act on intrinsic cholinergic neurons. The cellbodies of such afferents may be present in intrinsic plexa or within the sensory vagal nodose ganglion. VIP elicited relaxatory motor responses from the extrahepatic biliary tree, not influenced by blockade of cholinoceptors or beta-adrenoceptors. Stimulation of beta-adrenoceptors, or selective stimulation of beta 2-adrenoceptors caused dose-dependent relaxatory motor responses, which were antagonized by specific blockade. Stimulation of beta-adrenoceptors following selective blockade of beta 2-adrenoceptors resulted in relaxation, most probably mediated by beta 1-adrenoceptors.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenergic beta-Agonists↗

Adrenergic and VIP-ergic relaxatory mechanisms of the feline extrahepatic biliary tree.

Relaxatory mechanisms of the extrahepatic biliary tree were investigated in anesthetized cats allowing separate recordings of the sphincter of Oddi, gallbladder and duodenal wall. Regional intra-arterial administration of vasoactive intestinal peptide (VIP) elicited dose-dependent relaxatory motor responses, which were not influenced by blockade of cholino- or beta-adrenoceptors, but were most probably due to activation of VIP receptors at the smooth muscle membrane. Efferent electrical vagal nerve stimulation unmasked relaxatory motor responses after previous blockade of muscarinic cholinoceptors. The neural transmission did not involve beta-adrenoceptors but was effectively antagonized after additional blockade with hexamethonium. Since both nerve terminals and ganglion cells with VIP-like immunoreactivity were abundant in the feline sphincter of Oddi, VIP is one possible transmitter candidate of the postganglionic inhibitory neurons. Non-selective activation of beta-adrenoceptors by isoprenaline or selective activation of beta 2-adrenoceptors by terbutaline also induced a dose-dependent relaxation of these regions. On a molar basis, relaxation via beta-adrenoceptors was 40-50 times less potent than via VIP. Both types of beta-adrenergic relaxation were antagonized by propranolol. The terbutaline-induced responses were selectively antagonized by beta 2-adrenoceptor blockade. To evaluate the role of beta 1-adrenoceptors, non-selective stimulation with isoprenaline was given; this relaxation was little influenced by blockade of beta 2-adrenoceptors but was completely antagonized by propranolol. In all experiments using beta-adrenoceptor antagonists these drugs each increased the basal tone of the preparation suggesting release of tonic inhibition exerted via beta-adrenoceptors.

Animals↗

VIP antisera inhibit the relaxatory motor responses of the feline sphincter of Oddi and gall-bladder induced by VIP or vagal nerve stimulation.

Regional administration of VIP elicited a dose-dependent relaxation of the feline sphincter of Oddi and gall-bladder. Relaxatory motor responses of these regions at efferent electrical stimulation of the vagal nerves were unmasked after atropine (resistant to propranolol but sensitive to hexamethonium). These findings in combination with the presence of a rich VIP-ergic innervation, including intrinsic VIP neurons, have made VIP a tentative post-ganglionic non-adrenergic, non-cholinergic neurotransmitter to these regions. The relaxatory motor responses elicited by VIP or vagal activation were selectively antagonized using regional administration of specific VIP antisera in support of this hypothesis.

Ampulla of Vater↗

Substance P in the control of extrahepatic biliary motility in the cat.

The effects of regional intra-arterial injections of substance P (SP) or efferent electrical stimulation of the vagal nerves on feline extrahepatic biliary motility were studied in anesthetized cats using a constant perfusion model. Each of these procedures elicited contractile motor responses of the gallbladder and the sphincter of Oddi. Since SP is present in feline vagal axons, these findings may indicate a role of SP in the vagal motor control of biliary motility. Immunocytochemically neurons with SP-like immunoreactivity were found in the smooth muscle layers of the biliary tree as well as adjacent to acetylcholinesterase-positive ganglion cells indicating either direct activation of smooth muscle cells and/or indirect activation via cholinergic neurons. Depending on the type of stimulation different SP mechanisms were demonstrated; exogenous SP induced contraction of both the sphincter and the gallbladder which were probably direct (resistant to atropine but sensitive to a SP analogue), while vagal stimulation elicited contraction of both regions via a mechanism sensitive to atropine and to a SP analogue.

Animals↗

An in vivo model for the simultaneous study of motility of the gallbladder, sphincter of Oddi and duodenal wall in the cat.

An in vivo model for the simultaneous study of motility of the gallbladder, sphincter of Oddi and the duodenal wall in species with an intraduodenal location of the sphincter has been developed. Gallbladder motility is registered by manometry, while trans-sphincteric flow and duodenal wall motility are recorded by perfusion methods. The sphincter of Oddi proper is totally uninfluenced by any mechanical procedures since the outflow of fluid is collected via a funnel-shaped human femoral vein graft fixed to the duodenal mucosa by tiny sutures peripheral to the sphincteric muscle. The motility of the duodenal wall influences the flow of saline through a small feline vein graft inserted across the duodenal wall. The method is described in detail as well as nerve stimulation experiments and some pharmacological tests (e.g. infusion of substance P) to demonstrate the usefulness of the method. With this method the physiology and pharmacology of this region can be investigated in species, which, like man, have an intraduodenal location of the sphincter of Oddi.

Ampulla of Vater↗