PubMed Health⌕ Search

Biomedical subjects

R H Riddell

Publications and source records attributed to R H Riddell.

At least 127 records · Page 7Linked to original sources
PubMed1979

Inflammatory tissue reaction in rabbit bowel injected with Crohn's homogenates.

Homogenates from the terminal ileum of a patient with Crohn's disease with granulomas were prepared as snap-frozen or fresh and were injected into the ascending colonic walls of New Zealand white rabbits. Control animals were injected with 1 per cent bovine serum albumin alone. The rabbit bowel was examined after 1 year, and lesions were noted in each of the rabbits injected with Crohn's disease homogenate, irrespective of the type of tissue preparation. The observed lesions were diffuse and occurred both at the injection site and in the terminal ileum. These changes were not noted in the control group. This work confirms earlier results in the same animal model and suggests that either fresh or snap-frozen homogenates will produce the intestinal lesion but that bovine albumin alone will not.

Animals↗
PubMed1979

Value of sigmoidoscopy and biopsy in detection of carcinoma and premalignant change in ulcerative colitis.

Of 111 carcinomas developing in 73 patients with ulcerative colitis, 46 (41.5%) arose in the rectum where they are directly accessible to sigmoidoscopy. Fifty-eight per cent of single carcinomas developed in the rectum. The extent and frequency of rectal dysplasia was assessed by examining slides of rectal mucosa with an eyepiece micrometer. Slides from 46 patients with carcinoma and 22 patients with dysplasia but no carcinoma in whom proctectomy or proctocolectomy had been carried out were examined by this method. Thirteen of 15 patients with carcinoma of the colon (87%) and 21/22 patients (95%) with large bowel dysplasia showed evidence only of rectal dysplasia. However, there was marked variability in the proportion of dysplastic rectal mucosa even in those patients with rectal carcinoma, while in some patients dysplasia was limited to a small focus. Because of the possibility of false negative biopsies due to sampling error, multiple biopsies should be taken to detect dysplasia. Their state should be recorded and deliberately varied at subsequent visits. Careful sigmoidoscopy and multiple biopsies in this study had potential value as an aid in the detection of 85-90% of all carcinomas. In practice the figure would almost certainly be lower due to intrinsic bias (see discussion) so that, although regular sigmoidoscopy and biopsy would be of great value when colonoscopy is not available, the latter should be included in any long-term programme of carcinoma prevention.

Biopsy↗
PubMed1979

Circumscribed eosinophilic gastroenteritis.

A case of eosinophilic gastroenteritis with peripheral blood eosinophilia and typical histology is described. The location, radiographic appearance, and gross pathologic appearance of the lesion were unique in that they resembled eosinophilic granuloma of the stomach. Also unique was the fact that the distal esophagus as well as the stomach was involved. This case demonstrates that eosinophilic gastroenteritis may involve any portion of the gastrointestinal tract and that the radiologic distinction between eosinophilic gastroenteritis and eosinophilic granuloma may not be as clear cut as previously thought.

Adult↗
PubMed1978

Radiological detection of colonic dysplasia (precarcinoma) in chronic ulcerative colitis.

Epithelial dysplasia occurring in long-standing ulcerative colitis is a precancerous lesion. Macroscopically it has a nodular or villous appearance or may be indistinguishable from the surrounding mucosa. An investigation into the radiological diagnosis of dysplasia, using in vivo and in vitro double-contrast examinations with magnification radiographic studies, correlated with the histological analysis, has been made in four patients. Characteristic radiological abnormalities have been identified in the areas of the mucosa associated with histologically proven dysplasia. These appearances include nodularity and irregular areas with sharply angulated edges which may represent enlarged areae colonicae. The demonstration of these changes is an indication for endoscopic examination and biopsy of the suspicious area.

Adult↗
PubMed1978

Malignant transformation of esophageal columnar epithelium.

This report describes two patients with esophageal columnar epithelium (Barrett's esophagus) in which microinvasive adenocarcinoma developed. Case 1 had multiple foci of carcinoma in situ contiguous with epithelium resembling gastric and intestinal mucosa. Case 2 had signet-ring type adenocarcinoma. Surveillance for malignant transformation in columnar esophageal epithelium should be routinely performed, and because of its focal nature, multiple biopsies and cytologic examination should be carried out. The presence of carcinoma in situ should lead to consideration of excision of the affected esophagus.

Adenocarcinoma↗
PubMed1977

Ultrastructure of the "transitional" mucosa adjacent to large bowel carcinoma.

The transitional mucosa immediately adjacent to large bowel carcinoma was examined in 13 patients by scanning electron microscopy (SEM), and this was correlated with transmission electron microscopy (TEM) and light microscopy (LM). Marked abnormalities were present in this mucosa in 9/13 patients with distortion and loss of the normal architecture. Examination of adenomas showed abnormalities also to be present adjacent to the neoplastic mucosa. In all patients, the transitional mucosa was compared with two pieces of normal mucosa; in one patient, typical changes of transitional mucosa were found in this region. In the remaining patients, normal mucosa by SEM was found to consist to large deep furrows (primary crypts) as well as the crypts of Lieberkuhn (secondary crypts). The secondary crypts structure showed marked individual variation between patients but one type was present in nine patients. It is uncertain whether this is a pattern with a high incidence in the general population, or whether patients with this type of mucosa are particularly predisposed to large bowel carcinoma. SEM may, therefore, play a part in identifying patients particularly likely to develop large bowel carcinoma.

Adenoma↗
PubMed1977

Intestinal lymphoma complicating dermatitis herpetiformis.

A case is reported of a patient with dermatitis herpetiformis who has developed an intestinal lymphoma and a bladder carcinoma during the course of his illness. When considered in conjunction with three recently reported cases it is suggested that intestinal lymphoma may complicate the enteropathy of dermatitis herpetiformis.

Dermatitis Herpetiformis↗
PubMed1977

Usefulness of rectal biopsy in inflammatory bowel disease.

With careful "standardized" technique and proper handling, rectal biopsies can be useful diagnostic and therapeutic adjuncts in the initial evaluation and then long term observation of patients with chronic inflammatory bowel disease.

Biopsy↗
PubMed1977

The production of an unusual tissue reaction in rabbit bowel injected with Crohn's disease homogenates.

Recent reports have suggested a transmissible factor in the etiology of Crohn's disease, which had yet to be confirmed. The specificity of the transmission was tested with a disease control of ulcerative colitis as well as normal bowel. Twenty New Zealand White rabbits received inoculum of tissue homogenates from the terminal ileum of normal, ulcerative colitic, and Crohn's disease patients. This inoculum was injected into the wall of the ascending colon and the animals were examined after one year. Changes were noted consistently only in those animals receiving the Crohn's disease inoculum. These changes consisted of thickened bowel wall with increased mucosal folds, thickened mesenteric fat with some creeping, irregular areas of thin colonic mucosa, and hyperplastic mesenteric lymph nodes. The terminal ileum distant from the inoculum site was smooth with atrophic changes only in the Crohn's inoculated group of animals. These animals also had discrete collections of macrophages in colon or sacculus, mucosal and submucosal edema, and chronic inflammation of the colon. However, the characteristic features of Crohn's disease were not reproduced.

Animals↗
PubMed1975

Oesophagoscopy, biopsy, and acid perfusion test in diagnosis of "reflux oesophagitis".

The results of fibreoptic endoscopy have been assessed retrospectively in 71 patients referred for consideration of the oesophagus as the possible or probable cause of their symptoms. Gross endoscopic abnormality was uncommon but friability of the mucosa was seen in about half of the patients with typical symptoms of "reflux-pain" and a quarter of those without. The combination of radiological reflux and endoscopic abnormality--that is, true reflux oesophagitis--was seen in only a third of the patients with typical symptoms though much less commonly in those with atypical symptoms. Histological abnormality was common but did not relate well to symptom pattern. The results of the acid perfusion test were significantly related to symptom pattern though overlap was observed between the two symptomatic groups. Six of these patients had had or were awaiting surgery to correct reflux and they all had uniformly positive findings. This study confirms the value of the acid perfusion test in clarifying the diagnosis of reflux pain, espcially if the symptoms are difficult to assess. Endoscopy and biopsy added little further information of diagnostic value and could probably be reserved for the small minority of patients who have special problems such as blood loss or dysphagia or where clarification of a radiological lesion is required.

Adult↗
PubMed1975

The solitary ulcer syndrome of the rectum.

The solitary ulcer syndrome of the rectum is not rare but often remains unrecognised. A greater awareness of the condition will lead to more frequent diagnosis. The aetiology remains unproven but the evidence would suggest that a combination of prolapse, trauma and ischaemia, caused by excessive straining at stool may be important factors. The reasons for straining at stool are also obscure but in some cases a failure in the normal behaviour of the puborectalis may be involved. The history and clinical features of the condition are described, and the pathogenesis discussed.

Adolescent↗