Innervation of the child urinary bladder

Muscle strips from the fundus, trigonum and distal ureters obtained from children at operations for vesico-ureteric reflux were studied using histochemical and immunohistochemical methods, and electrical nerve stimulation in an organ bath. A rich supply of cholinergic nerves was found and despite a partial atropine resistance the neurophysiological experiments indicated that the transmitter causing contraction of the detrusor muscle is acetylcholine. Imipramine, which is used in the treatment of enuresis, had no anticholinergic effect on the bladder in the doses used clinically. The adrenergic innervation was very sparse except around the ureter orifices. No contractile alpha-adrenoceptors could be detected but beta receptor mediated relaxation was found, which was neither of the beta 1 nor beta 2 type. A third type of beta receptor is postulated. Peptidergic nerves containing vasoactive intestinal peptide, VIP, were demonstrated in a few nerve terminals running along bundles of smooth muscle. No nerves containing enkephaline, somatostatine or substance P were found. VIP affected the detrusor muscle indicating a possible role as a modulator of transmitter action, while substance P had no effect. The anticholinergic and calcium antagonistic drug terodiline inhibited all muscle activity, whether it was induced by nerve stimulation, cholinergic drugs or a potassium rich solution, making it suitable for treatment of diurnal enuresis.     

The effect of naloxone on the preoperative gastric volume and pH

The effect of 4 mg oral naloxone on preoperative gastric volume and pH of gastric aspirate was studied in a double-blind, randomized study. Twenty patients received 10 ml of naloxone (4 mg) mixed with 10 ml of orange juice, and 20 patients received 10 ml of isotonic saline mixed with 10 ml of orange juice, 2 h before surgery. Gastric content was obtained immediately after intubation of the trachea. No significant difference in gastric volume and pH of gastric aspirate was found between the two groups. It is concluded that naloxone does not affect gastric emptying and gastric acid secretion to a degree great enough to protect against aspiration of gastric contents into the lungs.     

Systemic Absorption and Block after Epidural Injection of Ropivacaine in Healthy Volunteers

Background: For local anesthetics, the process of removal from the site of administration influences the duration of anesthesia and the risk for systemic toxicity to develop. The systemic absorption of epidural ropivacaine and the time profile of sensory and motor block were studied in healthy volunteers.

Methods: Nine persons simultaneously received 150 mg ropivacaine hydrochloride (7.5 mg/ml) epidurally and 40 mg deuterium-labeled (sup 2 H sub 3)ropivacaine hydrochloride (0.25 mg/ml) intravenously. Peripheral arterial and venous plasma samples were collected, and assessments of sensory and motor block were made.

Results: The arterial plasma concentrations increased faster than the venous concentrations, with 50% higher maximum concentrations after both intravenous and epidural administration. The absorption was biphasic. A correlation was seen between the duration of sensory block and the slower absorption half-life; that is, the longer the half-life, the longer the duration. The extent of spread varied among the volunteers, with the median upper block level not exceeding T12. The motor block (Bromage score 1) was of slower onset (median, 0.4 h) and of shorter duration (median, 4.1 h) than the sensory block (onset, 0.2 h; duration, 6.5 h at L2 medians).     

Neuroendocrine differentiation in male breast carcinomas.

The presence of neuroendocrine differentiation, as expressed by cellular chromogranin immunoreactivity, was investigated in paraffin-embedded tissue material from 51 consecutive cases of male breast carcinoma. From six of these cases electron microscopic studies were included. Chromogranin-immunoreactive cells were present in solid cords and delineated tubular structures. Ultrastructurally, dense core secretory granules could be detected. The expression of neuroendocrine differentiation was 45%, which is between two and eight times higher than reported for female breast carcinomas by other investigators. The present findings suggest that male breast carcinoma is an exclusive tumour disease showing both similarities and discrepancies when compared to its female counterpart.     

Distribution and effects of pituitary adenylate cyclase activating peptide in cat and human lower oesophageal sphincter.

1. The localization, tissue concentrations, and effects of pituitary adenylate cyclase activating peptide (PACAP) 27 and 38 were investigated in cat and human lower oesophageal sphincter (LOS), and compared with those of vasoactive intestinal peptide (VIP) and helospectin. 2. PACAP-immunoreactive nerve structures were found in the cat and human LOS, with an abundance in the circular smooth muscle layer. PACAP 27-immunoreactivity was often co-localized with VIP-immunoreactivity. 3. In cat tissue, PACAP (PACAP 27 plus PACAP 38) concentrations were 50 fold lower than VIP concentrations; in human tissue they were 10 fold lower. 4. PACAP 27, PACAP 38, helospectin I, and VIP induced concentration-dependent relaxations in circular smooth muscle preparations from cat and human LOS. The order of potency was: VIP > helospectin I > or = PACAP 27 > PACAP 38. NG-nitro-L-arginine, scopolamine, or apamin, did not influence the relaxant effects of PACAP 27 or VIP. 5. In cat preparations, both cyclic AMP and cyclic GMP levels were increased after exposure to PACAP 27 and helospectin I, whereas exposure to VIP was followed by an increase in cyclic AMP levels only. In human preparations, there was an increase in cyclic AMP levels without any change in cyclic GMP levels. 6. These results suggest that in the cat and human LOS, PACAP 27 and VIP can occur within the same nerve structures. PACAP 27 has a potent relaxant action, but its functional importance has to be established.     

Elevated levels of the rapid inhibitor of plasminogen activator (t-PAI) in acute myocardial infarction

Myocardial infarction is frequently caused by acute coronary thrombosis. A previous study in patients three years after myocardial infarction has shown twice as high concentrations of the rapid inhibitor of plasminogen activator (t-PAI) as in healthy controls. The present study involves 29 patients with acute onset of myocardial infarction. Already on admission the mean concentration of t-PAI was 16.5 +/- 7.4 units/ml as compared to 7.5 +/- 2.3 in healthy controls. It is presently unknown if moderately elevated t-PAI levels contribute to a delay of the spontaneous thrombolysis of the coronary occlusion, thus promoting the development of myocardial infarction.