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Biomedical subjects

N Jordan

Publications and source records attributed to N Jordan.

57 records · Page 4Linked to original sources
PubMedDate not supplied

Interaction of norethindrone and isoniazid following their oral co-administration to the minipig.

Following the oral co-administration of isonicotinic acid hydrazide and norethindrone to minipigs, the hydrazone of norethindrone was detected in plasma as its p-methoxybenzaldehyde derivative, using a high performance liquid chromatographic technique. The suspected precursor of the hydrazone of norethindrone was isonicotinyl hydrazone of norethindrone, a reaction product probably formed between norethindrone and isonicotinic acid hydrazide in the acid environment of the stomach. An in vitro liver metabolite of isonicotinyl hydrazone of norethindrone was isolated following derivatization with p-methoxybenzaldehyde and characterized by high resolution mass spectrometric and radiochemical techniques. The results demonstrated that the hydrazone of norethindrone is a metabolite of isonicotinyl hydrazone of norethindrone.

Administration, Oral↗
PubMedDate not supplied

The adherent gastric antral and duodenal mucus gel layer thins with advancing age in subjects infected with Helicobacter pylori.

BACKGROUND: Peptic ulceration and Helicobacter pylori infection increase with advancing age. In the upper gastro-intestinal tract the first line of mucosal defence is the adherent mucus gel layer. OBJECTIVE: We have examined, using a novel histological fixation technique, the thickness of the adherent mucus gel layer (1) in the gastric antrum and (2) in the duodenum in relation to advancing age and H. pylori status. METHODS: The subjects had macroscopically normal stomach and duodenum at endoscopy. Measurement of the gastric antral mucus thickness was carried out on four antral biopsy specimens from within 2 cm of the pylorus (H. pylori positive n = 25, negative n = 21). The duodenal mucus thickness (D1) was measured from two biopsy specimens (H. pylori positive n = 7, negative n = 13). All specimens were snap frozen and cryostat sections stained using a modified PAS/AB stain. RESULTS: In all sections the mucus layer was continuous. In both duodenum and gastric antrum, the mucus thickness was not significantly different between H. pylori positive and H. pylori negative age-matched samples. In duodenum and gastric antrum from H. pylori negative subjects, there was no correlation between mucus thickness and age. However, in H. pylori positive subjects, there was a significant thinning of the adherent gastric antral mucus gel layer (p = 0.005, r = -0.54) and the duodenal mucus thickness (p<0.001, r = -0.99) with advancing age. CONCLUSION: This study shows a significant thinning of the adherent mucus gel layer in H. pylori positive individuals, as stomach and duodenum age. In those without H. pylori, the mucus gel thickness is preserved in stomach and duodenum.

Aged↗