SUMMARY Responses of the cricopharyngeal sphincter to graded intraluminal distension were studied in order to determine its response threshold and to define the functional relationship between the sphincter and oesophageal body. Nine normal subjects underwent manometric study using a multilumen tube with an attached inflatable balloon sited 10 cm below the sphincter. Sphincteric and oesophageal motor responses to six graded balloon inflations were recorded in each subject. The sphincter responded to distension with increasing rise in pressure, from a median value of 42-5 mmHg at lowest levels of distension to 95 mmHg at maximal tolerated distension. Non-swallow related contractile activity was stimulated in the oesophageal body proximal to the distension and increased in quantity as inflation progressed. Distal propagation of this secondary activity was progressively inhibited with increasing distension. These interrelated changes thus show the normal upper oesophageal clearance responses to intraluminal distension. It is suggested that their more widespread application, in addition to standard manometric techniques, might provide a more rational evaluation of those patients suspected to have impaired oesophageal clearance, but in whom standard manometry is non-diagnostic.The cricopharyngeal (upper oesophageal) sphincter, situated at the intersection of the airway and the first part of the alimentary tract' is formed mainly by the cricopharyngeal muscle, with additional fibres from the circular muscle of the oesophagus distally and the inferior pharyngeal constrictor proximally.23The coordinated relaxation and contraction of this sphincter constitutes an integral part of normal deglutition, ensuring the passage of a bolus from the pharynx into the oesophagus, and additionally forms a dynamic barrier to prevent oesophagopharyngeal reflux and spillover into the tracheobronchial tree. This latter function is of particular importance because breakdown of this mechanism may be related to oesophagopharyngeal regurgitation and aspiration pneumonitis. '34 Measurements of the resting sphincter pressure and its relationships to the oesophageal body have previously been attempted,>' but the data are incom-

The relation between intrarectal volume and pressure during increasing rectal distension by a latex balloon were studied on repeated occasions in 10 healthy adult volunteers to define variations within and between individuals. A wide intersubject variation in the maximum tolerable volume (58-908 ml) and pressure (12-2-108.8 The protocols for the studies performed were approved by the local district ethics committees and all participants gave their informed consent before the study.Ten healthy adults (eight men and two women aged 18-21 years) with no previous history of gastrointestinal disorder were studied. Twenty six patients (Table I) suffering from the irritable bowel syndrome underwent similar examination. The diagnosis was made from an appropriate history'0' and was supported by a normal physical examination, sigmoidoscopy, full blood count, erythrocyte sedimentation rate, biochemical profile, and barium enema. PREPARATION FOR STUDYAll subjects and patients were requested to defecate immediately before the study and digital examination of the rectum was always performed before insertion of the manometry assembly to check that the rectum was clear of faeces.

SUMMARY Oesophageal motor responses to intraluminal distension were studied manometrically in 16 healthy volunteers and in nine patients with disordered swallowing, who had prolonged oesophageal clearance without structural abnormality. In the normal subjects distension was associated with an increased number of secondary contractions above the balloon, decrease of all contractile activity below the balloon and was accompanied by an aborally propulsive force which occurred independently of the perception of discomfort. Cholinergic blockade abolished the proximal distension induced contractile response, but did not affect primary peristalsis. Despite normal sensory thresholds, proximal excitatory responses to distension were absent in six and distal inhibition was absent in seven patients. These results show that the normal human oesophagus responds to distension with a proximal enhancement of propulsive motor activity, mediated through a cholinergic pathway. This may be defective in some patients with disordered oesophageal transit. Investigation of the motor responses to intraluminal distension may thus be a useful adjunct to standard manometry for studying patients with suspected oesophageal clearance dysfunction and might allow identification of disordered enteric nervous control.

SUMMARY The motor responses of the small intestine to intraluminal distension were studied proximal and distal to an inflatable balloon in 13 normal volunteers. During fasting, distension rapidly induced a persistent localised inhibition of distal contractile activity with a small proximal increase. Proximally, phase III activity was unaffected during distension but its propagation across and appearance below the balloon was inhibited. Upon deflating the balloon a normal motor pattern rapidly returned. Similar changes were observed during distension in the fed state. The changes in the motor pattern resemble those of the intrinsically mediated 'peristaltic reflex', studied in animals, and suggest that in man the response to balloon distension may also be mediated through an intrinsic mechanism. A patient with a visceral neuropathy, studied in a similar manner, had no inhibition of distal motor activity during distension, suggesting a functional defect of the enteric nerves. Further observations of the motor responses to distension in similar patients seem indicated to determine the usefulness of this technique for evaluating enteric nervous system function when an abnormality is suspected.

481 CommentThe survey clearly disclosed widespread public ignorance of the elementary facts relating to testicular cancer. Hence, not surprisingly, most of the respondents had never heard ofa self examination procedure and only five men (1-3%) examined themselves regularly. The biased nature of the study group in favour of better education highlights the findings. We should reasonably expect a better appreciation of health matters in these men than in the general population.The positive aspects of the results indicate the way for future action. The affirmed interest by nine out of 10 Patients with ulcerative colitis tend to be non-smokers,' and it has been suggested that smoking may protect against the disease.2 Colonic mucus in ulcerative colitis has been shown to be qualitatively and quantitatively abnormal,3 and cigarette smoking is known to produce hypersecretion and modification of respiratory mucus by systemic as well as local effects.4 We have therefore investigated colonic mucus production in vitro in patients with ulcerative colitis and assessed the possible influence of smoking. Patients, methods, and resultsPatients attending for routine colonoscopy answered a detailed questionnaire which included details of smoking habits and other relevant social and clinical data. Patients were then divided into a group with ulcerative colitis and a "control" group (comprsing 63 subjects with diverticular disease or irritable bowel syndrome, 18 with colonic carcinoma, and 40 with colonic polyps). Clinical diagnosis was confirmed by independent histological examination offixed biopsy material.The control group contained 70 non-smokers and 51 current smokers (42%), while the ulcerative colitis group contained 71 non-smokers and 11 current smokers (13%), emphasising the infrequency of smoking among patients with ulcerative colitis.Biopsy specimens were obtained from the descending colon (adjacent to the site used for histological diagnosis) and, using established tissue culture techniques, incubated in Roswell Park Memorial Institute culture medium 1840 containing 10 mg fetal calfserum per ml, 100 ig gentamicin per ml, and 1-25 FtCi (46-2 kBq) D-[l1-H]-glucosamine hydrochloride (specific activity 2 2 Ci (81-4 GBq)/mmol) at 37'C in a mixture of 5% carbon dioxide and 95% air for 24 hours. Glucosamine is incorporated into the carbohydrate chains of the newly synthesised mucus glycoproteins. After tissue culture the specimens were homogenised and an aliquot of the homogenate assayed for total protein concentration by a modified L^owry method. The mucus glycoproteins were extracted by precipitation with trichloroacetic acid and phosphotungstic acid.5 The resultant protein and glycoprotein pellet was solubilised and synthesised mucus quantified by liquid scintillation counting of the newly incorpo,rated tritiated glucosamine. After extensive ,dialysis to remove unincorporated label the culture medium was precipitated and coUinted in the same way. The results from the biopsy and medium fractions were combined to give total...