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Biomedical subjects

K G Porter

Publications and source records attributed to K G Porter.

At least 19 recordsLinked to original sources
PubMed1997

Gastric as well as duodenal biopsies may be useful in the investigation of iron deficiency anaemia.

BACKGROUND: Iron absorption is known to be impaired in the setting of gastric achlorhydria, yet gastric atrophy is not usually considered an aetiological factor for iron deficiency anaemia. We aimed to determine the prevalence of achlorhydric gastric atrophy in patients with iron deficiency and no identifiable source of gastrointestinal blood loss, and to assess whether gastric, as well as duodenal, biopsies should be routinely performed in these patients. PATIENTS: Forty-one consecutive patients with iron deficiency anaemia and no specific gastrointestinal symptoms or evidence of a bleeding lesion on faecal occult blood testing or upper gastrointestinal or colonic endoscopy. METHODS: As well as routine duodenal biopsies, samples were taken from gastric corpus and antrum for evidence of gastric atrophy. Achlorhydria was considered to be present if plasma gastrin measured on a sample obtained with the patient fasting was over 200 ng/l. Serum was tested for intrinsic factor and gastric parietal cell antibodies. RESULTS: Haemoglobin concentrations ranged from 4.1 to 10.9 g/dl. Eight (20%) of the 41 patients had corpus-predominant or generalized atrophy and high plasma gastrin levels, of whom six had serum intrinsic factor and/or gastric parietal cell antibodies: two also had Giardia lamblia organisms in duodenal biopsies. Four other patients (10%) had villous atrophy of the duodenum. CONCLUSIONS: As well as confirming the importance of seeking coeliac disease in patients with iron deficiency anaemia, our results suggest that achlorhydric gastric atrophy is also a common association. Gastric biopsies should be taken in patients with no other explanation for anaemia. The finding of Giardia organisms in two achlorhydric patients, with a possible contributory role, suggests that duodenal biopsies should be obtained even if serum coeliac-related antibodies are absent.

Adolescent↗
PubMed1996

Screening for coeliac disease as a possible maternal risk factor for neural tube defect.

Coeliac disease is an important cause of malabsorption, particularly of folic acid, in adults. We investigated the possibility that it might be a maternal risk factor for neural tube defect (NTD)-associated pregnancy by screening affected mothers using serum endomysial antibody (EmA) which has high sensitivity and specificity for coeliac disease. One (1.6%) of 60 patients was EmA positive and had a diagnosis of coeliac disease confirmed by the finding of villous atrophy on jejunal biopsy. In conclusion, the majority of NTD-associated pregnancies are not associated with maternal coeliac disease and our study is additional evidence that abnormalities of folic acid metabolism rather than absorption are the most important risk factors for NTD. Further studies are needed to determine whether the coeliac disease prevalence among women with NTD-affected pregnancy is higher than that of the general population.

Adult↗
PubMed1994

Lewis phenotype, secretor status, and coeliac disease.

Patients who cannot secrete ABO and Lewis blood group antigens into body fluids, an ability controlled by a single gene on chromosome 19, are known to be at increased risk of certain autoimmune diseases associated with human leucocyte antigen (HLA) markers. This study investigated the possibility of an association with coeliac disease using red cell Lewis (Le) blood group phenotype to infer secretor status. Among 73 patients with coeliac disease who had Le a or b antigen, 48% were non-secretors (Le a + b-) compared with 27% of 137 blood donors (p = 0.004: odds ratio 2.49, 95% confidence intervals 1.37 to 4.51) and 26% of 62 medical and nursing staff controls (p = 0.014: odds ratio 2.65, 95% confidence intervals 1.27 to 5.50). Clinical characteristics did not differ between secretors and non-secretors with coeliac disease. Thus, the non-secretor state is significantly associated with coeliac disease, suggesting that genes on chromosome 19 may directly or indirectly participate in conferring susceptibility.

Celiac Disease↗
PubMed1993

Secretor status and Helicobacter pylori infection are independent risk factors for gastroduodenal disease.

The hypothesis that non-secretors of ABO blood group antigens, a group shown to be more susceptible to certain bacterial infections, may be at greater risk of gastroduodenal disease because of increased susceptibility to Helicobacter pylori infection was investigated. Of 101 patients with symptoms of dyspepsia who were undergoing endoscopy, 32% were non-secretors (determined from Lewis blood group phenotype), 36% had endoscopically visible gastroduodenal disease (antral gastritis, gastric ulcer, erosive duodenitis, duodenal ulcer or some combination), and 58% had H pylori detected in antral biopsy specimens. Non-secretors and patients with H pylori infection were significantly more likely to have gastroduodenal disease (p = 0.02 and p = 0.002 respectively). There was, however, no significant association between secretor status and H pylori infection, logistic regression analysis confirming that these were independently associated with gastroduodenal disease. Overall, the relative risk of gastroduodenal disease for non-secretors compared with secretors was 1.9 (95% confidence intervals 1.2, 3.2). Non-secretion of ABO blood group antigens is not related to H pylori infection but is independently and significantly associated with endoscopic gastroduodenal disease. The mechanism of this remains to be explained.

ABO Blood-Group System↗
PubMed1992

Detection of undiagnosed coeliac disease with atypical features using antireticulin and antigliadin antibodies.

Eighteen patients with a variety of non-gastrointestinal symptoms were incidentally found to have circulating antireticulin antibody and on subsequent testing were also positive for antigliadin antibody. They prospectively underwent jejunal biopsy to determine whether or not they had coeliac disease. Their age range was 21-79 years (mean 42 years). Enteropathy was present in 13 (72 per cent) and was always associated with circulating IgA antigliadin antibody. Enteropathy was not present in the five cases who had only IgG antibody. Clinical improvement occurred in eight of 11 patients who complied with a gluten-free diet and was paralleled by an improvement in the mucosal histology in seven of eight who were re-biopsied. The most remarkable cases were two patients who presented with severe debility and no apparent haematological or biochemical abnormalities, and who subsequently made a dramatic recovery on a gluten-free diet. It is concluded that antireticulin antibody detected by routine autoantibody screening and confirmed to have IgA antigliadin antibody specificity is a useful indicator of an otherwise undiagnosed enteropathy. This serves to emphasize that the condition can sometimes be associated with atypical features and significant morbidity.

Adult↗
PubMed1991

Predictive value for coeliac disease of antibodies to gliadin, endomysium, and jejunum in patients attending for jejunal biopsy.

OBJECTIVE: To investigate the extent to which the detection of antibodies to gliadin, endomysium, and jejunum predicts the eventual diagnosis of coeliac disease according to the revised ESPGAN diagnostic criteria in a group of patients in whom there is a high suspicion of coeliac disease. DESIGN: Clinical assessment and laboratory analysis of patients with suspected coeliac disease. SETTING: Gastroenterology department of teaching hospital. PATIENTS: 96 adults with suspected coeliac disease attending for jejunal biopsy. MAIN OUTCOME MEASURES: Diagnosis of coeliac disease with the revised criteria of the European Society of Paediatric Gastroenterology and Nutrition in patients with and without antibodies associated with coeliac disease. RESULTS: 28 patients had a clinical diagnosis of coeliac disease, seven of other gastrointestinal diseases, and 12 of miscellaneous diseases; 49 had no diagnosis. Gliadin IgA detected by ELISA was found in all patients with coeliac disease and none of those without, giving a sensitivity, specificity, positive and negative predictive values, and predictive efficiency of 100% for diagnosing coeliac disease within the group. Endomysial IgA was found in 25 (89%) patients with coeliac disease and jejunal IgA in 21 (75%); neither IgA was found in patients without coeliac disease. CONCLUSION: Detection of gliadin IgA by ELISA and to a lesser extent the endomysial IgA should allow better selection of patients for jejunal biopsy and thus make diagnosing coeliac disease simpler and more efficient.

Adolescent↗
PubMed1989

An audit of hospital admissions for acute upper gastrointestinal haemorrhage.

A retrospective survey was made of all 189 patients admitted with acute upper gastrointestinal haemorrhage to the Belfast City Hospital in one year. The commonest single reason for admission was peptic ulcer disease, but this was lower than in other published series from the United Kingdom. Overall mortality was 4.8%. The majority of patients did not require either blood transfusion or surgery. There may be potential benefits of endoscopic haemostatic techniques to deal with this condition.

Acute Disease↗
PubMed1988

Survival of coliforms and bacterial pathogens within protozoa during chlorination.

The susceptibility of coliform bacteria and bacterial pathogens to free chlorine residuals was determined before and after incubation with amoebae and ciliate protozoa. Viability of bacteria was quantified to determine their resistance to free chlorine residuals when ingested by laboratory strains of Acanthamoeba castellanii and Tetrahymena pyriformis. Cocultures of bacteria and protozoa were incubated to facilitate ingestion of the bacteria and then were chlorinated, neutralized, and sonicated to release intracellular bacteria. Qualitative susceptibility of protozoan strains to free chlorine was also assessed. Protozoa were shown to survive and grow after exposure to levels of free chlorine residuals that killed free-living bacteria. Ingested coliforms Escherichia coli, Citrobacter freundii, Enterobacter agglomerans, Enterobacter cloacae, Klebsiella pneumoniae, and Klebsiella oxytoca and bacterial pathogens Salmonella typhimurium, Yersinia enterocolitica, Shigella sonnei, Legionella gormanii, and Campylobacter jejuni had increased resistance to free chlorine residuals. Bacteria could be cultured from within treated protozoans well after the time required for 99% inactivation of free-living cells. All bacterial pathogens were greater than 50-fold more resistant to free chlorine when ingested by T. pyriformis. Escherichia coli ingested by a Cyclidium sp., a ciliate isolated from a drinking water reservoir, were also shown to be more resistant to free chlorine. The mechanism that increased resistance appeared to be survival within protozoan cells. This study indicates that bacteria can survive ingestion by protozoa. This bacterium-protozoan association provides bacteria with increased resistance to free chlorine residuals which can lead to persistence of bacteria in chlorine-treated water. We propose that resistance to digestion by predatory protozoa was an evolutionary precursor of pathogenicity in bacteria and that today it is a mechanism for survival of fastidious bacteria in dilute and inhospitable aquatic environments.

Animals↗