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Biomedical subjects

A Ferguson

Publications and source records attributed to A Ferguson.

At least 235 records · Page 13Linked to original sources

Precipitins to dietary proteins in atopic eczema.

Precipitating antibodies to foods have been assayed in three groups of patients with atopy. Forty-five per cent of patients with atopic eczema and IgE-mediated food allergy had precipitins to foods in their serum compared with only 15% of patients with atopic eczema without evidence of food allergy, and 16% of patients with atopic asthma and/or rhinitis. It is likely that this results from increased intestinal permeability in the group with eczema and food allergy.

Adult↗

Human intestinal mucosal mast cells: expanded population in untreated coeliac disease.

Previous retrospective studies of intestinal mucosal mast cells in coeliac disease have given divergent results, and we have recently reported that inappropriate methodology could account for these discrepancies. In this prospective study, mucosal mast cell counts were performed in Carnoy fixed, peroral jejunal biopsy specimens from patients with coeliac disease, both untreated and treated with a gluten-free diet; and from controls (mainly irritable bowel syndrome). Mean mucosal mast cell count in 27 control subjects was 146/mm2, SD 29. Significantly higher values were obtained in untreated coeliac disease (mean 243, SD 41, p less than 0.001) returning to the normal range in coeliacs treated with a gluten-free diet with normal jejunal biopsy morphology. In seven patients mucosal mast cell counts were performed in multiple jejunal biopsies, and these showed that mucosal mast cell distribution was not patchy. There was no evidence of degranulation of intestinal mucosal mast cells under the conditions of routine biopsy (overnight fast). An increase in mucosal mast cells in untreated coeliac disease may be one explanation for the high number of IgE positive stained cells in the intestinal mucosa that has been reported by some authors.

Celiac Disease↗

Nature of the inflammatory cell infiltrate in duodenitis.

Counts of lamina propria and intraepithelial cells, lymphoid and polymorphonuclear, have been performed on semithin sections of endoscopic biopsies from the duodenum of patients with ulcer-associated duodenitis, with non-specific duodenitis, and from controls. In both types of duodenitis there were significant increases in lamina propria counts of plasma cells, lymphocytes and eosinophils, and in intraepithelial lymphocyte counts, when compared with controls. In control specimens, neutrophil polymorphs were very infrequent but a substantial neutrophil polymorph infiltration of the epithelium and lamina propria was present in both types of duodenitis. In biopsies from areas of duodenitis scanning electron microscopy showed the presence of cells, which are probably neutrophil polymorphs, on the luminal surface of the mucosa. Abnormalities in cell counts were present only in biopsies taken from visually inflamed areas of the duodenal bulb. These values returned to normal after healing of duodenitis with cimetidine. This study highlights the complex nature of the mucosal cellular infiltrate in in duodenitis, particularly the striking increase in polymorphonuclear leucocytes. Histopathological features of ulcer-associated and non-specific duodenitis are identical.

Cell Count↗

Twitch depression and train-of-four ratio after antagonism of pancuronium with edrophonium, neostigmine, or pyridostigmine.

During N2O-O2-halothane anesthesia pancuronium (3 mg/70 kg) was antagonized with neostigmine (2.5 or 5 mg/70 kg), pyridostigmine (10 or 20 mg/70 kg), or edrophonium (50 or 100 mg/70 kg) in 36 human subjects (6 in each group). Reversal was attempted at 10% spontaneous recovery of muscle twitch, which was measured using train-of-four stimulation. When first twitch tension was less than 70% of the control it was found that for the same tension, the train-of-four ratio was greater with edrophonium than with neostigmine, and greater with neostigmine than with pyridostigmine. It was concluded that the three antagonists have different mechanisms of action. In comparison with neostigmine, edrophonium is more and pyridostigmine is less effective at presynaptic (or fade) receptors.

Adolescent↗

T-cell mediated immunity in food allergy.

There are many T-cells within the intestinal mucosa, and histopathology, applied to biopsies of intestinal mucosa taken before and after food reintroduction, provides information on possible cell-mediated immunity to foods within the gut. Food sensitive enteropathies occur in man and in domestic animals, particularly in the young. Our hypothesis is that these are related to a relative deficiency of suppressor T-cells. There is no evidence that T-cell-mediated immunity to foods plays a part in severe atopic eczema, even in patients with clinical evidence of associated food allergy and high titres of IgE antibodies to foods.

Adult↗

Red cell folate levels, food antibodies and reticulin antibodies in farmer's lung--is there an association with coeliac disease?

Indirect evidence of enteropathy has been sought in a group of 57 subjects with farmer's lung (FL) by clinical questionnaire, estimation of red cell folate levels, the presence of precipitating antibodies to various food antigens and detection of reticulin antibodies. One subject was found who had villous atrophy and responded clinically to gluten withdrawal. There were two subjects with low red cell folate levels and multiple food antibodies, and one subject with reticulin antibodies and multiple food antibodies. Enteropathy is infrequent in subjects diagnosed clinically as having farmer's lung but seems to be more common than would be expected by chance. The mechanism has yet to be elucidated.

Adolescent↗

Immunological responses to fed protein antigens in mice. II. Oral tolerance for CMI is due to activation of cyclophosphamide-sensitive cells by gut-processed antigen.

Mice fed ovalbumin develop specific systemic hyporesponsiveness. This oral tolerance is abrogated by cyclophosphamide pretreatment, and the mechanism of abrogation could be either via T suppressor cells or via damage to the gut epithelium. A serum transfer protocol was used to examine the site of action of cyclophosphamide in this system. Serum was collected from ovalbumin-fed mice and transferred into recipients which were then parenterally immunized with ovalbumin in Freund's complete adjuvant. Serum transfer suppressed the delayed-type hypersensitivity (DTH) responses but not the antibody responses of the recipients. Cyclophosphamide pretreatment (100 mg/kg) of recipients (but not of donors) abrogated this suppressor effect. Parenteral administration of ovalbumin in a range of doses did not induce immunological hyporesponsiveness. It is suggested that absorption across the gut mucosa leads to generation of fragments of ovalbumin that induce suppressor cells selective for DTH.

Administration, Oral↗

Immunogenicity of foods and food additives--in vivo testing of gums arabic, karaya and tragacanth.

An inexpensive animal model is described, for investigation of the immunogenicity of substances such as food additives. Inbred mice were immunised with antigen emulsified in complete Freund's adjuvant, and specific cell-mediated immunity subsequently measured by a footpad swelling test. This method has been applied in an investigation of the immunogenicity of the exudate gums, gum arabic, gum karaya and gum tragacanth. These substances are capable of eliciting an immune response which is comparable to the specific immune responses elicited by a protein antigen, e.g. hens' egg ovalbumin. Purification of commercially available gum preparations led to a significant (P less than 0.005) reduction of the immune response under in vivo test conditions.

Allergens↗

Antagonism of pancuronium in renal failure: no recurarization.

Neuromuscular transmission was measured using train-of-four stimulation, during and after anaesthesia, in 20 patients with end-stage renal failure. Neuromuscular blockade was provided with pancuronium in single doses of either 3 or 6 mg per 70 kg, and antagonized at 10% recovery with atropine and neostigmine 2.5 mg per 70 kg. Reversal was followed by progressive recovery of muscle twitch in every patient during the 3 h of the study. Recovery was more rapid after the smaller dose of pancuronium and was inversely correlated with the duration of blockade. It is concluded that, when pancuronium is antagonized with neostigmine in patients with renal failure, neuromuscular transmission recovers without evidence of recurarization. However, when large doses of pancuronium are antagonized with neostigmine 2.5 mg, recovery may be insufficient to ensure normal ventilatory function.

Adult↗

A mobile intensive care unit based on a standard ambulance trolley bed.

An inexpensive, versatile Mobile Intensive Care Unit is described. By designing the unit around a standard ambulance trolley no running costs are incurred in the maintenance of a purpose-built unit based on an ambulance used purely for this purpose. The equipment is portable and compact and can be transported by any available means, including a taxi, to the referring hospital. Only when the patient is ready for transfer is an ambulance asked for, making the minimum use of emergency ambulance time. It contains all the equipment necessary to monitor and ventilate artificially a critically ill patient during transfer and all the drugs and disposables to treat any emergencies that may arise in this period.

Equipment Design↗

Jejunal villous atrophy with morbid obesity: death after jejunoileal bypass.

A 49-year-old woman with morbid obesity was found to have subtotal villous atrophy in an operative jejunal biopsy, taken when a jejunoileal bypass was created. After the operation, the patient developed marked weight loss, vomiting, hepatic failure, and a bizarre mental state with sudden losses of consciousness. Six months after the first operation the bypass was reversed but the patient developed hepatorenal failure and died one week after the second operation. The histological features of several biopsies of jejunum were typical of a gluten sensitive enteropathy. This, previously subclinical, small bowel disease may have contributed to her hepatic failure and death by interfering with jejunoileal adaptation. In the absence of any of the other, rarer, causes of villous atrophy, this woman appears to have had coeliac disease.

Celiac Disease↗

Features of small intestinal pathology (epithelial cell kinetics, intraepithelial lymphocytes, disaccharidases) in a primary Giardia muris infection.

In an attempt to correlate host and parasite-related events occurring during the course of a primary Giardia infection in the mouse we have measured epithelial cell kinetics, enzymes, and intraepithelial lymphocytes at different stages of the infection. New methods were developed for the accurate measurement of parasite numbers and distribution within the gut. In jejunum a modest decrease in villus length and intraepithelial lymphocytes at week 1 preceded a pronounced disaccharidase deficiency at week 2, the time of maximum trophozoite numbers, whereas crypt lengthening and increased cell production became maximal at week 3. As trophozoite numbers fell the intraepithelial lymphocyte count and disaccharidase values rose. With the exception of the intraepithelial lymphocyte count, which followed the same pattern as in jejunum but two weeks later, the changes seen in the ileum were the opposite of those in jejunum, suggesting rapid ileal adaptation. The results indicate that the disaccharidase deficiency associated with giardiasis is likely to represent a direct effect of the parasite on the brush border rather than enterocyte immaturity, whereas the intraepithelial lymphocyte response reflects host immunity to the parasite. Profound adaptive changes occur throughout the small intestine in response to a relatively localised insult.

Animals↗