Total Mucosal Thickness Research Articles

Quantitative Analysis of Small Intestinal Mucosa in Cow's Milk‐Sensitive Enteropathy

SummaryThe appearance of the small intestinal mucosa in cow's milk protein intolerance (CMPI) was studied using quantitative morphometry. The parameters under study were the numbers of eosinophil cells in the lamina propria and epithelium, villous height, crypt zone depth, villous height/crypt zone depth ratio, and total mucosal thickness. Tracings of whole sections were analysed using a suitably programmed minicomputer linked to a digitising table. Small bowel biopsy specimens from children with untreated CMPI, from children before and after clinical relapse on cow's milk challenges, and from children with resolved CMPI were compared to each other, to those from control infants, and to those from children with coeliac disease. No change of diagnostic significance could be found in the number of lamina propria eosinophil cells, but levels of intraepithelial eosinophils were significantly increased following cow's milk challenge. Quantification of mucosal dimensions confirmed the presence of a cow's milk‐sensitive enteropathy and established the finding of a thin mucosa in CMPI regardless of clinical disease activity. Mucosal thickness was not different from control values following resolution of the disease. In coeliac disease mucosal thickness was significantly greater than in CMPI (apart from young children with untreated coeliac disease whose mucosa was not thicker than that of children with untreated CMPI) but not different from control values. It is suggested that in CMPI there is a limitation in the capacity of crypt cells to compensate for the loss of villous epithelium.

Eimeria mitis in mixed infections with E. acervulina and E. brunetti in the fowl.

Eimeria mitis and E. acervulina affect different areas of the intestine. Young chicks received E. mitis with or without E. acervulina in doses ranging from 2 to 128 X 10(4) oocysts. Mixed infections produced significantly more severe effects on growth than single infections of either species. The ratio of villus height to total mucosal thickness was reduced throughout the intestine in birds which received the mixed infection. E. mitis and E. brunetti affect the same area of the intestine. Single infections of E. brunetti in a range of doses from 1 . 25 to 20 X 10(3) oocysts produced a similar reduction in growth. When 20 X 10(3) oocysts of E. mitis were inoculated simultaneously, the effect on growth was not so severe and the oocyst output of both species was reduced. E. brunetti, superimposed 1, 2 or 3 days after an E. mitis infection, produced no greater effect on growth than E. mitis alone. Similarly, infections of E. mitis, superimposed on E. brunetti had no greater effect on growth than the latter species alone. Oocyst output of E. brunetti in superimposed infections was not reduced but peak output was delayed.

Intestinal fatty acid esterification activity in jejunoileal bypass patients

In four patients undergoing reversal of jejunoileal bypass we compared functional (in continuity) with bypassed intestine in order to determined the effects of luminal contents. Total mucosal thickness, villus height, and crypt depth, as well as in vitro fatty acid esterification activity were determined. Morphological studies in segments exposed to luminal contents revealed that the ileum had a greater mucosal thickness than the jejunum (p less than 0.001) and that the difference was reflected in both villus height and crypt depth (p less than 0.001). The functioning segments of both jejunum and ileum had a greater mucosal thickness than corresponding bypassed segments consequent to a difference in villus height (p less than 0.001) but not crypt depth. Despite similar exposure to luminal contents, total fatty acid esterification was significantly higher (p less than 0.001) in the functioning jejunum than in the ileum. Jejunum incontinuity possessed higher esterification activity than bypassed jejunum. These results indicate that 1) luminal contents are the most important modulator of intestinal fatty acid esterification activity and the absence of luminal contents in bypassed intestine leads to a significant reduction in esterification activity, 2) the jejunum and ileum possess intrinsic differences in esterification activity even when both are exposed to an identical luminal environment.

Intestinal mucosal changes following induced hypothyroidism in the developing rat.

In this study, morphological changes which occur in the small intestine of hypothyroid rats are described. Hypothyroidism was induced during the first 24 h postnataly. - Samples from duodenojejunal and ileocecal junctions were taken, and histologic, histomorphometric, and ultrastructural studies were performed. The most prominent feature was the decrease of the villous height and total mucosal thickness. At electron microscopic level, microvillous height was also markedly decreased. These changes probably represent a direct effect of hormonal deprivation upon the intestinal mucosa, combined with the effect that hypothyroidism may have on the villi.

Morphometric Studies of the Small Intestine Following Jejuno-ileal Shunt Operation

In five patients in whom a jejuno-ileal by-pass had been previously performed for massive obesity, a relaparotomy was performed because of subjective complaints or unsatisfactory weight reduction. At the reoperation morphometric studies were made of the functioning segments and the by-passed intestine. Length and circumferential measurements were taken, and the villous height and mucosal thickness were measured from histological biopsies. The results were compared with the findings in a control group. After shunt operation adoptive hypertrophy in the functioning remnant, a considerable length growth and dilatation of the gut, as well as a marked increase in villous height and total mucosal thickness, were demonstrated. These adaptive changes seem to be more marked in the distal part of the small intestine. No atrophy of the mucosa could be demonstrated in the excluded intestinal loop.

Enteropathy in adult protein malnutrition: light microscopic findings

Light microscopy evaluation of the intestinal abnormalities seen in 35 severely malnourished adults revealed changes which are common to other well-documented enteropathies. These included shortening, widening and fusion of the villi, lost convolution of the nuclear line, and diminished epithelial cell height. With Masson's trichrome stain, dense material was seen to have accumulated in a subepthelial location in villi (as described in other enteropathies), in crypts, and perivascularly around the capillaries of the lamina propria. Two findings however appear to characterize the severely malnourished state: a consistent, significant reduction of intestinal mucosal thickness, and in many cases atrophy of the crypts. Statistical analysis of the total mucosal thickness data does not justify five but rather three histological categories. With protein repletion as the sole therapeutic modality, 17 patients in which adequate biopsy samples were available at its completion showed significant amelioration of the aforementioned histological abnormalities, as well as normalization of their previous absorptive defects. The mild enteropathy of severe protein malnutrition must be considered in the differential diagnosis of malabsorption in a tropical setting.

Intestinal structure and function after small bowel by-pass in the rat.

1. To study further the influence of luminal nutrition on small bowel structure and function, segments of rat jejunum and ileum were completely excluded from intestinal continuity by Thiry-Vella by-pass operations. The effect of partial deprivation of luminal nutrition was also studied in jejunal segments that had been surgically transposed to a distal position in the intestinal tract. 2. Macroscopically, by-passed jejunum and ileum both became narrowed and atrophic, whereas the intestine in continuity showed hypertrophic changes similar to those seen after intestinal resection. 3. In by-passed intestine the pattern of villi changed from mucosal ridges to ‘fingers’ and ‘leaves’. Although villous height and total mucosal thickness were both reduced, light microscopy showed that even 6 months after exclusion from intestinal continuity villous morphology was still retained. 4. Epithelial-cell migration rate and turnover time were diminished in both jejunum and ileum after by-pass. In intestine in continuity the migration rate was increased, but the turnover time remained the same as in controls. 5. In by-passed jejunum, in vivo glucose absorption diminished progressively with time, but did not change in excluded ileal segments. 6. After ileo-jejunal transposition, the jejunum showed no major morphological changes, but glucose absorption became significantly depressed. 7. These results further support the concept that intraluminal nutrition exerts a major influence on cell turnover, villous morphology and absorptive function in the small intestine.

Jejunal biopsy in malignant disease.

SUMMARYThe appearance of the small bowel mucosa and mucosal measurements are described in 45 patients with various malignant conditions and compared with the findings in 25 control subjects. The mean villous height and mean total mucosal thickness were significantly reduced in the patients with malignant disease. The mucosa in malignant disease was normal in 38%, and showed simple atrophy in 31%, partial villous atrophy in 29% and subtotal villous atrophy in 2% of cases. The mucosal changes were related to the duration of illness and the degree of loss of weight. They were less frequently detected in patients with bronchial carcinoma. The presence of metastases, the treatment given, the interval before death and the presence of steatorrhœa were not related to the abnormal mucosa. Steatorrhœa was detected in one‐third of the patients, but it was usually slight. Steatorrhœa did not account for weight loss and abnormalities in the small bowel mucosa appeared to be unrelated to the steatorrhœa.

Measurements of small intestinal mucosa obtained by peroral biopsy

Measurements of total mucosal thickness, villus heights and widths, surface cell heights and villus surface were obtained from mucosal biopsy specimens of the jejunum in 139 patients, consisting of control subjects and patients with postgastrectomy steatorrhoea, pancreatic steatorrhoea, regional enteritis, coeliac disease and idiopathic steatorrhoea. In the last two groups, measurements were evaluated separately for untreated subjects and for those treated with a gluten-free diet. The results of all measurements were abnormal in those with coeliac disease and idiopathic steatorrhoea groups and although there was an improvement in the average values after treatment with a gluten-free diet, they remained abnormal when compared to those in all other groups. There were minor mucosal changes in the patients with postgastrectomy steatorrhoea, pancreatic steatorrhoea and regional enteritis.