No abstract

The thermic effect of 1.67 MJ (400 kcal) of carbohydrate (glucose), fat, protein and mixed meal were examined in 11 lean and 11 obese subjects by indirect calorimetry. The changes in metabolic rate in response over 90 min period (30-120 min after the meal) to the different meals were compared with that seen after a similar volume of low calorie drink. The thermic effects of glucose and protein were not significantly different between lean and obese subjects. Obese subjects showed very little increase in metabolic rate following ingestion of fat (-0.9 +/- 2.0%, mean +/- SEM) and this was significantly different from that seen in lean subjects (14.4 +/- 3.4%). The thermogenic response to mixed meal was also significantly lower in obese subjects when expressed as percentage change (12.9 +/- 2.3% compared to 25.0 +/- 4.8%). There was no evidence for delay in gastric emptying times for glucose and fatty meal in the six obese subjects in whom these were measured. We conclude that obese subjects show a reduced thermogenic response to fat.

A new dynamic technique for the investigation of anorectal function has been developed. This involves radiological visualization of the rectum during voiding of a semisolid radio-opaque contrast medium, and simultaneous measurement of the intrarectal pressure and electrical activity of the external anal sphincter. The method has been used to study patients (n = 16) with profound difficulty passing formed stool. It has demonstrated an abnormal increase in the activity of the puborectalis and superficial and sphincter muscles during voiding in these patients, compared with normal subjects (n = 6). The inability to void was associated with failure to widen the anorectal angle on straining.

SUMMARY The cause of solitary rectal ulceration has been investigated using a method that radiologically visualises rectal voiding whilst simultaneously measuring intrarectal pressure and external anal sphincter electromyographic activity. Control subjects and patients with the solitary rectal ulcer syndrome, both with and without mucosal ulceration, have been studied. A high incidence of rectal prolapse (94%) was present in the patients who voided. Overactivity of the anal sphincter during evacuation contributed to the fact that patients with mucosal ulceration required higher intrarectal pressures to void than the controls and the patients without mucosal ulceration. The results indicate that a combination of rectal prolapse and a high voiding pressure may act to cause the mucosal ulceration in this syndrome by exposing the rectal wall to a high transmural pressure gradient.It is suggested that the solitary rectal ulcer syndrome (SRUS) forms part of a spectrum of disorders (the 'mucosal prolapse syndrome') that is characterised by histological changes in the rectal mucosa,' and is caused by prolapse of the rectal mucosa.' A relationship between solitary rectal ulceration and rectal prolapse, which is often clinically occult, has been well demonstrated" but if the mucosal prolapse theory of the aetiology of SRUS is to be accepted it is necessary to be able to explain why only a small percentage of patients with rectal prolapse ulcerate, and the majority do not. It may be that other factors act in combination with the prolapse to cause the mucosal damage seen in patients with ulceration.The objectives of this study were, therefore, to test the mucosal prolapse theory of the aetiology of the SRUS, and should it prove correct, to identify the additional factors responsible for the mucosal ulceration. To do this we have investigated the anorectal function of control subjects and patients with a diagnosis of SRUS confirmed by rectal biopsy, using a technique that radiologically visualises the

The prognostic utility of 24-hour plasma MIF concentration in predicting PN has major clinical and healthcare resource implications. Its mechanistic pathway may afford novel therapeutic interventions in clinical disease by using blocking agents to ameliorate the systemic manifestations of AP.