Selective recruitment of lymphocyte subsets to the inflamed appendix.

Total lymphocyte counts and the distribution of lymphocyte subsets were determined in peripheral venous blood and appendiceal mononuclear cells from 60 patients who underwent appendicectomy for the clinical diagnosis of appendicitis. A significant peripheral lymphopenia was observed in the 46 patients with histologically confirmed acute appendicitis which was accompanied by an increase in the appendiceal lymphocyte concentration. There was an even greater depletion of CD45RO+ (memory) T lymphocytes in peripheral blood and an increase in the inflamed appendix. Reciprocal changes were observed in the CD45RA+ (naive) T lymphocyte subset. These changes were reflected in the local arterial and venous CD45RA and CD45RO T lymphocyte subsets. Proliferation studies showed an expanded functional repertoire of T lymphocytes in the inflamed appendix. Selective recruitment of memory T lymphocytes from the peripheral blood to the inflamed appendix was demonstrated.

Long-term results of treatment of peptic stricture of the oesophagus with the Angelchik prosthesis.

An Angelchik prosthesis was inserted in 43 patients with a peptic stricture above a hiatus hernia; 16 showed columnar lining of the oesophagus below the stricture. The mean preoperative bore of strictures was 8.7 mm. Within months, and without dilatation, 33 strictures shortened, 35 widened and of these 13 disappeared with a mean bore of 11.7 mm. In the long term, three more strictures resolved but three recurred. Final measurements gave a mean bore of 12.2 mm. The mean follow-up was 3.5 years. Symptomatic and radiological assessments suggested that the prosthesis was less effective when sited in the chest.

Measuring change in surgical practice.

We reviewed the work of a single general surgical firm over six years--about 11,500 patient episodes. Although the workload remained approximately constant, a severe reduction in the number of available beds was accompanied by a marked change towards shorter duration of stay. This affected particularly the elective cases. Previous authors, when trying to predict requirement of hospital beds, have accepted that duration of stay and number of beds available are independent variables; this was not what we observed.

Blood platelet serotonin following enterectomy in rats.

The role of the intestine as a source of platelet serotonin was investigated. Radioactive serotonin precursor. 5-Hydroxytryptophan was injected into enterectomised and sham-operated rats. Blood samples were taken at time intervals and serotonin uptake was estimated by radioactive counting. Soon (1-2 hrs) after surgery and under sodium pentobarbital anaesthesia, platelet 5HT activity was higher in enterectomised rats than in controls. The intestine may not be the major source of platelet serotonin.

Removal of 5-hydroxytryptamine by rat lungs.

Isolated rat lungs perfused with Krebs solution removed free radioactive 5-Hydroxytryptamine (5 HT or serotonin) from the fluid perfusing them. However, when platelets labelled with 111In-oxine to tag them individually, and with 14C-labelled 5 HT were also perfused via the lungs, there was no significant removal of the labelled 5 HT from the platelets. Paper chromatography showed that 46.7% of the platelet bound 5 HT was metabolished to an unidentified material. Rat lungs remove free 5 HT from plasma but not when it is platelet bound.

McBurney's point--fact or fiction?

Anthropometric measurements were performed on 51 normal, supine, barium enema examinations to determine the position of the lower pole of the caecum and the base of the appendix relative to palpable bony landmarks (the anterior superior iliac spine and the symphysis pubis). Four quadrants were defined (iliac, umbilical, inguinal and pelvic) by the intersection of the right lateral line and the interspinous line (the line joining the left and right anterior superior iliac spines). The position of the lower pole of the caecum was iliac in 12%, inguinal in 37%, and pelvic in 51%. The appendix or appendix stump was visualised on 53% of the barium examinations. The position of the appendix was iliac in 15%, umbilical in 15%, inguinal in 11%, and pelvic in 59%. The positions of the lower pole of the caecum and base of the appendix are lower and more medial than previously described. 70% of appendices were found to lie inferior to the interspinous line, contrary to established surgical teaching, which assumes McBurney's point to be the surface landmark for the appendix.

Pursuing efficiency in surgical practice.

To examine fluctuations in numbers of patients on surgical wards the dates of admission from January of each of the 5556 patients admitted from 1 January 1985 to 31 December 1987 were examined during computerised audit of a single surgical firm. The numbers of patients under the care of the firm fluctuated widely, often exceeding the 38 beds nominally available. Duration of stay varied from two days or less (3062 admissions) to more than a month (163 admissions). One patient was in hospital for 278 days. The patients admitted for more than a month (2.9% of the total) filled 28% of the beds; not all these patients were elderly. A further increase in throughput of patients undergoing elective operations might be achieved by always admitting patients on the day of operation, and perhaps by discharging patients even sooner than at present. Efficiency would increase but so would overall costs.

On the nature of the receptor mediating the action of 5-hydroxytryptamine in potentiating responses of the mouse urinary bladder strip to electrical stimulation.

Superfused mouse bladder strip responded to electrical stimulation (ES) by twitch contractions. These contractions were potentiated by 5-hydroxytryptamine (5-HT; 0.03-3.0 microM). Three tryptamine analogues were tested for their ability to potentiate the responses to ES and their relative activities were compared with values in the literature. 5-Carboxamidotryptamine was more potent than 5-HT, N-omega-methyl 5-HT was about equipotent, and alpha-methyl 5-HT was much less potent. Exogenous noradrenaline did not reduce the effect of 5-HT, although it reduced the response of the tissue to ES. The maximum increase in tissue tension evoked by 5-HT was unaltered by phentolamine (1 microM) or bretylium (25 microM). These results show that 5-HT did not act on the bladder by inhibiting the release of catecholamines from intrinsic nerves. The effect of 5-HT proved very resistant to attempts to block it with conventional 5-HT antagonists. Several antagonists were studied including ketanserin, methysergide, methiothepin, and MDL 72222 but even at concentrations as high as 1 microM none of them exhibited any marked inhibitory effect against the action of 5-HT. At 10 microM some compounds showed activity, but none abolished the effect except methiothepin - and its action was not surmountable by increasing the concentration of 5-HT. Thus the effect of 5-HT on the bladder was not mediated by 5-HT receptors of types 'M', 'D' or 5-HT2.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for purinergic transmission in mouse bladder and for modulation of responses to electrical stimulation by 5-hydroxytryptamine.

Electrical stimulation (ES) contracted superfused mouse bladder, and 10(-7) M tetrodotoxin (TTX) abolished the twitches without impairing responses to acetylcholine (ACh) or beta,gamma-methylene ATP. ES acted largely through nerves which were not cholinergic, adrenergic or histaminergic. They may be purinergic because the bladder was contracted by stable analogues of ATP, and after desensitisation by a high concentration of alpha,beta-methylene ATP the response to ES was selectively reduced. 5-Hydroxytryptamine (5-HT) at 0.03-3 X 10(-6) M and tetraethylammonium (TEA) at 0.1-10 X 10(-3) M potentiated responses to ES, on average by 64% and 182%. Pempidine had no effect on responses to ES. The action of TEA was different from that of 5-HT; potentiation of responses was greater than could be produced by 5-HT, and whereas 5-HT did not increase responses to ACh, TEA markedly increased twitch tensions. The mode of action of 5-HT is not clear.

A quantitative assessment of results with the Angelchik prosthesis.

The Angelchik antireflux prosthesis was assessed in 15 unpromising patients, 12 of whom had peptic strictures of the oesophagus. Radiological techniques were used to show the effect of the device on gastro-oesophageal reflux, and on the bore and length of strictures. Twelve months later (range 6-24) most patients were well satisfied with the operation, and all considered it had been worthwhile; there was radiological evidence of reduction in reflux and remission of strictures. The device never surrounded the oesophageal sphincter; in all but 1 case it encircled a tube of stomach.

Loss of 5-hydroxytryptamine from mammalian circulating labelled platelets.

1. Platelets were obtained from three species of animal: rats, rabbits and dogs. They were labelled with (111)In oxine to tag individual platelets and with (14)C-labelled 5-hydroxytryptamine (5-HT). Doubly labelled platelets from rabbits and dogs were returned to their donors; in the case of rats the platelets were injected intravenously into other, identical rats. At time intervals from 2 to 64 hr, blood samples were drawn and platelets were collected. (111)In and (14)C were separately counted. In some experiments animals received the 5-HT precursor, 5-hydroxytryptophan (5-HTP) I.P. (for rats and rabbits) or subcutaneously (for dogs) in a dose of 20 mg/kg daily to accelerate synthesis of 5-HT.2. (111)In disappeared in approximately an exponential fashion in all experiments and the rate of disappearance was not affected by treatment with 5-HTP. The half-life for (111)In in four control rats was 18.7 hr and in five rats treated with 5-HTP was 17.8 hr. In rabbits the half-life was 20.4 hr for eight control and 21.2 hr for seven treated with 5-HTP. In the dogs the half-life was 21.0 hr for control and 27.7 hr for experiments with 5-HTP. In control rats, the (14)C behaved like the (111)In. However, in control rabbits the half-life for (14)C was 38.0 hr which is significantly longer than for (111)In (P < 0.005). (14)C also disappeared more slowly than the (111)In in the dogs.3. In all species treatment with 5-HTP accelerated the disappearance of the (14)C approximately three-fold. This was not a reserpine-like effect because the platelets contained more, not less 5-HT than usual.4. In an attempt to discover the fate of 5-HT disappearing from circulating platelets, experiments were made in which platelets from one rat were doubly labelled, and were then injected into two other rats from the identical strain; one of the recipients received daily I.P. injections of 20 mg/kg of 5-HTP. The other rat in each pair acted as a control.5. Results from twelve control rats showed that the (14)C/(111)In ratio in several tissues deviated from that found in platelets. Deviations occurred in both directions; in the spleen, liver and kidney the ratio was significantly lower than in the platelets (P < 0.01), whereas in the adrenals, thyroid, bladder and gut the ratio was significantly higher (P < 0.05 for thyroid, < 0.01 for others). In the gut, however, the ratio was significantly raised (P < 0.01) only at 5 hr.6. Administration of unlabelled 5-HTP to another twelve rats greatly reduced the (14)C in platelets. Under these conditions many tissues in addition to those above had a higher ratio of (14)C/(111)In than platelets. These tissues included muscle, skin, salivary gland, kidney, heart, aorta, testis and seminal vesicle. As with platelets, the absolute counts of (14)C/g of tissue decreased significantly after 5-HTP administration (platelets by 67%, brain by 56%, pancreas by 49%, lungs by 39%, liver by 37%, kidney by 29%, testis by 23% and seminal vesicle by 22%). On the other hand, there were significant rises of 93% in the skin and 21% in the muscle. Paper chromatography showed that 73-86% of the (14)C in tissues still behaved like 5-HT, except in the bladder and adrenals which contained unidentified material.7. It is concluded that under normal conditions platelets deposit 5-HT in specific tissues, notably gut, adrenals and thyroid. When unlabelled 5-HTP is administered, the labelled 5-HT is deposited in a variety of tissues, and especially in the skin.