Angioplasty produced clinically worthwhile improvement for approximately 50% of patients. High incidence rates of extrarenal involvement and intrarenal disease and a high restenosis rate after stenting accounted for poor blood pressure control in the rest.

This study describes the angiographic findings in children with polyarteritis nodosa (PAN). Visceral angiograms of 25 children with PAN were reviewed retrospectively by two independent radiologists. In the PAN group, 40% of children had aneurysms demonstrated on selective renal angiography. Most aneurysms affected small and medium-sized arteries. There was agreement between radiologists regarding medium and large aneurysms ( K=0.81), but less so for smaller aneurysms. Overall, the presence of medium or large aneurysms was significantly associated with the presence of renal impairment and hypertension. Non-aneurysmal changes were detected more commonly on renal angiography than aneurysms in the PAN group. The most reliable non-aneurysmal signs were perfusion defects, the presence of collateral arteries, lack of crossing of peripheral renal arteries, and delayed emptying of small renal arteries. The sensitivity and specificity of renal angiographic diagnosis of PAN using aneurysms alone was 43% (SE 10%) and 69% (SE 14%) respectively. The sensitivity increased to 80%, and specificity fell to 50% for angiogram positivity defined as the presence of at least one of the most reliable non-aneurysmal signs irrespective of the presence of aneurysms. Aneurysms were also demonstrated on hepatic and mesenteric angiography, and non-aneurysmal signs were found on hepatic, mesenteric, and splenic angiography, although interobserver agreement for angiographic findings in these vascular beds was lower. It is important to consider both aneurysmal and non-aneurysmal angiographic signs, and to include examinations of several vascular beds when utilising angiography for diagnostic purposes in children with PAN.

MDCT is proposed as an alternative first-line investigation to locate lower gastrointestinal bleeding before placing the patient under observation or performing embolization or surgery.

Current evidence from experimental animals suggests that the colonic crypt is a clonal unit derived from, and maintained by, a single cell (Griffiths et al., 1988). Treatment of normal female TO strain mice with the colon-specific carcinogen dimethylhydrazine (DMH) results in a histochemically demonstrable loss of activity of the X-linked enzyme glucose-6-phosphate dehydrogenase (G6PD) in single, randomly distributed colonic crypts. This phenotypic change is uniform within the affected crypts, and its frequency is related to the dose of DMH treatment, strongly suggesting that it is the result of a carcinogen induced mutation at the G6PD locus on the active X-chromosome of a single primary crypt stem cell (Griffiths et al., 1988).A similar crypt-restricted phenotypic change has been demonstrated in normal human large bowel mucosa using the mild periodic acid-Schiff (mPAS) technique (Sugihara & Jass, 1986). This histochemical method distinguishes between 0-acetylated sialomucins, which are mPAS-negative, and non-0-acetylated sialomucins which stain a magenta colour (Veh et al., 1982). Sugihara and Jass (1986) found that in most human colons the goblet cell mucus is O-acetylated and mPAS-negative but that in a small proportion of individuals it is non-O-acetylated and diffusely mPAS-positive. However, in some cases with mPAS-negative colonic mucus glycoproteins they observed scattered individual mPAS-positive crypts. They were uncertain of the significance of this but interpreted it as a 'functional metaplasia'. A similar phenomenon has been identified by Hughes et al. (1986), who described a focal loss of immunoreactivity to a monoclonal antibody (3NM) directed against colonic goblet cells, again confined to scattered crypts in the human large intestine.Because the crypt-restricted phenotypic alterations described in these two reports are similar to the mutageninduced loss of G6PD activity in the colonic crypts of experimental mice, we considered that they may result from crypt stem cell mutation. If this were correct, the frequency of affected crypts would increase with exposure to environmental mutagens, and be age-related. The change might also occur more frequently in subjects with colorectal cancer. We have investigated this using the mPAS technique on histologically normal areas of resection specimens of the sigmoid colon and upper rectum from 30 adults (mean age 71.8 years, range 55-91) with primary large intestinal adenocarcinoma, 30 age-matched controls (mean age 71.3 years, range 52-90) with benign conditions of the sigmoid colon (diverticular disease 27, volvulus 3), and 18 infants or children (mean age 25 months, range 2 days to 9 years) with Hirschsprung's disease (16), intestinal atresia (1) or colonic duplication (1). One block of formalin-fixed, paraffin-embedded tissue from each resection margin of the colectomy specimens was taken and 5 im histological sections were cut at 50pm (Veh et al., 1982). In nine cases (three from each patient group) two adjacent levels were cut, one being stained by t...

The aim of this study was to evaluate the usefulness of CT of the brain in patients presenting with a psychiatric condition without focal neurological signs. The reports of 397 consecutive CT brain scans of patients presenting to two acute tertiary hospital psychiatric services over a 2-year period were assessed retrospectively. Of the 397 patients, 241 had psychosis, 87 had depression, 44 had bipolar affective disorder, seven had alcohol dependence, five had dementia, and the remaining 13 had a variety of diagnoses including personality disorder and transient ischaemic attack. Findings on 377 (95%) of the CT scans showed no abnormality. Specific abnormalities were described in 20 (5%) of the CT scans. Three scans showed non-specific minor abnormalities, which, when followed up by MRI, showed no relevant abnormality. All the abnormalities shown on CT were considered to be clinically unrelated to the patient's psychiatric condition. In conclusion, the pretest probability of finding a space-occupying lesion or other pertinent abnormality in patients presenting with psychiatric illnesses in this retrospective study appears not to be greater than that of the general population. The outcome of this study could be implemented to develop a clinical pathway for limiting assessment by CT for possible organic pathology in acute psychiatric illness.