SUMMARY The possibility that the small intestine may represent a reservoir for Clostridium difficile was studied, using segments of human jejunum collected at necropsy. Our results (three of 100 specimens positive for C difficile culture) support the hypothesis that C difficile can be found in human jejunum and that it adheres to the normal mucosa as a resident bacterium. These findings suggest that gastrointestinal disease caused by C difficile has an endogenous origin.The possibility that the small intestine might represent a reservoir for disease caused by Clostridium dificile was suggested by Taylor et al, when they isolated C difficile from a jejunal aspirate of a patient with chronic colitis.' This hypothesis was confirmed by our experience with a case of pseudomembranous enteritis with spared colon, in which we isolated C difficile from the patient's ileum obtained atTo elucidate these findings we carried out a study to verify the rate of isolation of C difficile from human small intestine using segments of jejunum that had been obtained at necropsy. Material and methods COLLECTION OF SPECIMENSOver six months one hundred segments of proximal jejunum were collected within 48 hours from 100 patients who had died. The specimens were about 10 cm long and macroscopically free from lesions. Each segment was placed in a sterile Petri dish and immediately sent to the bacteriology laboratory.The subjects had died from different diseases, none of them had had diarrhoea or other gastrointestinal symptoms in life. The mean age was 70 years (range 52-86); 90% of the patients had received treatment with antibiotics-that is, ,B-lactam antibiotics alone, or in conjunction with aminoglycosides. PROCESSING OF THE SPECIMENSTo remove the bacteria that were not firmly attached to mucosa each segment was carefully washed with 10cc of a sterile saline solution using a vortex mixer for 10 minutes.3 This procedure was repeated three Accepted for publication 18 March 1986 861 times for each sample, changing the container and the washing liquid each time. After this the segment was stretched and the mucosa removed with a sterile Iancet; the material obtained was used to inoculate a cycloserine-cefoxitin-fructose selective agar (CCFA) plate.4 The plates were screened for colonies characteristic of C difficile; all the cultures were incubated for at least five days before being discarded. The three washings from each segment were centrifuged for 10 minutes at 5000 rpm and the sediments were used to inoculate a CCFA plate. ResultsWithin 48 hours the cultures from the mucosa were positive for C difficile in three cases. Prolonged incubation of the other samples did not yield any additional positive results. None of the centrifugated washings yielded C difficile. The ages of the culture positive patients were 63, 60, and 74 years; all of them had received treatment with antibiotics.

Catecholamine (CA) secretion from the adrenal medullary tissue is a key step of the adaptive response triggered by an organism to cope with stress. Whereas molecular and cellular secretory processes have been extensively studied at the single chromaffin cell level, data available for the whole gland level are much scarcer. We tackled this issue in rat by developing an easy to implement experimental strategy combining the adrenal acute slice supernatant collection with a high-performance liquid chromatography-based epinephrine and norepinephrine (NE) assay. This technique affords a convenient method for measuring basal and stimulated CA release from single acute slices, allowing thus to individually address the secretory function of the left and right glands. Our data point that the two glands are equally competent to secrete epinephrine and NE, exhibiting an equivalent epinephrine:NE ratio, both at rest and in response to a cholinergic stimulation. Nicotine is, however, more efficient than acetylcholine to evoke NE release. A pharmacological challenge with hexamethonium, an α3-containing nicotinic acetylcholine receptor antagonist, disclosed that epinephrine- and NE-secreting chromaffin cells distinctly expressed α3 nicotinic receptors, with a dominant contribution in NE cells. As such, beyond the novelty of CA assays from acute slice supernatants, our study contributes at refining the secretory behavior of the rat adrenal medullary tissue, and opens new perspectives for monitoring the release of other hormones and transmitters, especially those involved in the stress response.

We report for the first time a novel electrochemical treatment applied to a glassy carbon electrode (GCE) during pnitrophenol (PNP) oxidation and dedicated to the limitation of electrode passivation by nitrophenol compounds oxidation. We propose an electrochemical process of direct phenol oxidation by starting the electrolysis at a very low potential, À1.2 V/SCE, in order to generate a soluble monomer, p-aminophenol, on the electrode surface. Then, paminophenol elaborated on the electrode surface in the place of oligomers, gives benzoquinone as a by-product and no film formation was observed. Furthermore, the presence of a p-NiTSPc (film of nickel tetrasulfonated phtalocyanine) coating permitted to increase two times the electrode sensitivity without passivation, too.