Reaction of rectal mucosa of celiac patients to direct contact with gluten

It is assumed that the colonic mucosa of celiac patients is not sensitive to gluten. This assumption has been supported by the absence of clinical manifestations of colonic involvement in patients with active celiac disease which, by itself, does not confirm insensitivity to gluten. Eight children, aged from 11 to 25 months, with an initial diagnosis of celiac disease were studied: in five children a definite diagnosis has already been confirmed. Rectal gluten challenge was done by means of retention enemas. A volume of 100 ml of a 10% gluten suspension in water was introduced into the rectum three times per day for 8 days; each enema was retained at least 1 h. Rectosigmoidoscopies and rectal biopsies were done before and at the end of the challenge period. The endoscopic appearance of rectal mucosa was normal in all the children either before or after gluten challenge. The means of total mucosal thickness, intraepithelial lymphocyte counts, mitotic crypt cell activity, and cellular infiltration of lamina propria increased after challenge; the mean of goblet cell/epithelial cell ratio in the surface epithelium decreased. The differences between each pair of means (before and after challenge), however, were not significant except for total mucosal thickness (p less than 0.05), the meaning of which is unclear. This study did not definitely demonstrate that the rectal mucosa of celiacs is insensitive to gluten. For practical clinical purposes, however, it behaves as such. This makes the rectal mucosa a useless tool for the final diagnosis of celiac disease.

Specificity of antibodies secreted by hybridomas generated from activated B cells in the mesenteric lymph nodes of patients with inflammatory bowel disease

Hybridomas have been prepared from active B cells in lymphoid tissue draining lesions of Crohn's disease (CD) and ulcerative colitis (UC), by fusion of fresh mesenteric lymph node suspensions with the murine JK myeloma. Two hundred and fifty nine immunoglobulin secreting hybridomas have been obtained from nine patients. The antibodies have been screened for binding to food antigens, sections of human gut, and bacteria including two unidentified acid fast isolates from CD lymph nodes. Autoantibodies, and antibodies to food antigens implicated by others in the aetiology of CD were rare, comprising 1.2%, and 2.5% respectively. Most donors yielded none of these. Thus neither food antigens nor autoantigens are major antigenic stimuli in nodes draining inflammatory bowel disease. On the other hand between 19% and 83% of supernatants from different donors bound to one or more bacterial genus. The mycobacteria and the CD isolates were amongst the genera to which most antibodies bound, though binding to E coli was more frequent. Significantly more CD than UC derived supernatants bound to BCG. As mycobacteria are not though to be part of the normal bowel flora, the high percentage of hybridomas secreting antibodies which bind to this genus is surprising.

Histopathological and radioautographical studies on the forestomach of F344 rats treated with butylated hydroxyanisole and related chemicals

Butylated hydroxyanisole, when fed to male Fischer 344 rats for periods of 9 days or more, led to forestomach epithelial cell necrosis and regeneration. Both the induced proliferation and the histopathological changes were considerably more prevalent in the prefundic region of the forestomach than in the mid-region. Using [Me-3H]thymidine, a specific DNA precursor, and radioautography it was shown that the effect of the antioxidant was apparently threshold at 0.25% in the diet after both 9 days and 3 months of treatment and that the proliferation was dependent on the continuous presence of the antioxidant in the diet at 3 and 6 months. Some other phenols and acids were investigated after 9-27 days' feeding; most induced some degree of epithelial cell proliferation in the rat forestomach, although some had a greater effect on the mid-region than on the prefundic region. These observations are discussed in terms of the likely relevance of butylated hydroxyanisole-induced forestomach tumours to the possibility that the antioxidant may lead to cancer in humans exposed to lower levels in their diet.

Short-term effects of various phenols and acids on the Fischer 344 male rat forestomach epithelium

A series of phenols and acids was fed to rats for 9 days to determine effects on the [methyl-3H]thymidine labelling index and the histological appearance of the forestomach. A variety of proliferative effects in the rat forestomach were observed which paralleled changes in the [methyl-3H] thymidine labelling index. The 3-tert-butyl isomer of butylated hydroxyanisole (BHA) was as effective as the food grade mixture. In the 4-hydroxybenzoic acid ester series, activity was not found either with the free acid or the methyl ester. With the ethyl, n-propyl and n-butyl esters activity in the perfundic region of the forestomach increased with alkyl chain length, the n-butyl ester being nearly as effective as BHA. In contrast, 4-methoxyyphenol and propionic acid demonstrated their greatest effects in the midregion of the forestomach, the action of propionic acid not being apparent until 21 or 27 days of treatment. It was also found that after a 9-day treatment involving coadministration of BHA and acetylsalicyclic acid, the overall effect of the antioxidant on the forestomach was greatly reduced.

Placenta previa and previous cesarean section

In a retrospective analysis over the six year period, January, 1973 to December, 1978, the incidence of placenta previa in cases with previous cesarean section (C.S.) was found to be 3.9 per cent as compared to an overall incidence of 1.9 per cent (p less than 0.01). The risk of placenta previa was greater in the pregnancy immediately following the cesarean section. The incidence of a morbidy adherent placenta was also significantly higher in these cases.

The influence of game animals on the distribution and feeding habits of glossina pallidipes in the Lambwe Valley

The role of game animals as important hosts of some species of tsetse, including Glossina pallidipes, has been studied in detail in the Lambwe Valley area of Kenya. A large population of G. pallidipes existed in association with a varied community of game animals in the study area, and the investigation was designed to determine which of the hosts available to G. pallidipes were actively selected and whether the preferred hosts influenced the distribution of the tsetse population. Bushbuck (Tragelaphus scriptus) was found to be the preferred host of G. pallidipes and there was a positive correlation between the distribution of these two species. Buffalo and roan antelope were also selected for food but, because of their behavioural characteristics, neither was continually available to the tsetse population and they had no influence on its distribution.

A technique for the bioassay of insecticide deposits on leaf and bark samples in relation to tsetse control operations

During tsetse control operations it may be necessary to determine the effective toxicity and persistence of insecticide residues on vegetation. A simple method for preparing samples of twig bark for bioassay and an exposure apparatus that has been found very satisfactory for exposing tsetse flies to residues on leaves and bark are described. The apparatus is easily manipulated and involves little handling of the test material.