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Biomedical subjects

S Pelloni

Publications and source records attributed to S Pelloni.

At least 19 recordsLinked to original sources
PubMed2005

Why downfield proton chemical shifts are not reliable aromaticity indicators.

Traces of magnetizability, traces of magnetic shielding at the hydrogen nuclei, and nucleus-independent chemical shift are not reliable aromaticity quantifiers for planar conjugated hydrocarbons. A measure of aromaticity is provided by the out-of-plane tensor components, whose magnitude is influenced by the pi-ring currents. The failure of nucleus-independent chemical shift in this regard was proved for the molecule shown in the abstract graphic, sustaining a diatropic pi-current. The validity of the ring-current model is reaffirmed. [structure: see text]

Journal Article↗
PubMed2005

Ring current effects on nuclear magnetic shielding of carbon in the benzene molecule.

The differential Biot-Savart law of classical electrodynamics was applied to develop a ring current model for the magnetic shielding of the carbon nucleus in benzene. It is shown that the local effect of the pi currents, induced by a magnetic field normal to the molecular plane, on the sigmaC out-of-plane shielding tensor component vanishes. However, approximately 10% of sigmaC is due to the shielding contributions from pi current density in the region of the other carbon atoms. Magnetic shielding density maps obtained via quantum mechanical procedures confirm the predictions of the classical model.

Benzene↗
PubMed2004

Ring-current models from the differential Biot-Savart law.

The differential Biot-Savart law provides simple models for the pi ring currents induced in diatropic and paratropic planar conjugated molecules by a perpendicular magnetic field. The model predictions are confirmed by ab initio maps of nuclear magnetic shielding density. The effects on the protons and on the ring carbon atoms from the closest and furthest segments of the current loop are easily interpreted. [structure: see text]

Journal Article↗
PubMed1985

[Misoprostol and cimetidine in the treatment of duodenal ulcer. A multicenter Swiss double-blind study].

The efficacy and tolerance of misoprostol a synthetic prostaglandin E1 analogue-and of cimetidine were evaluated in the treatment of duodenal ulcer following a double blind multicenter design. A group of Swiss gastroenterologists recruited 119 patients with endoscopically proven acute duodenal ulcer. They were enrolled and treated according to a uniform protocol either with misoprostol 4 X 50 micrograms daily, with misoprostol 4 X 200 micrograms daily or with cimetidine 4 X 300 mg daily. Patients who were healed after 4 or 8 weeks were followed during 6 months. Cumulative healing rates at 4 weeks in groups receiving misoprostol 200 micrograms, misoprostol 800 micrograms or cimetidine 1200 mg daily were 42%, 58% and 71% respectively. Patients treated with cimetidine showed a more rapid improvement of symptoms than patients treated with misoprostol. Symptomatic recurrences after ulcer healing occurred in almost 40% of the patients within 6 months, irrespective of the type of acute ulcer treatment. Risk factors for slowed healing and increased rate of recurrence were evaluated in the present study, and the results were compared with the results of two previous trials performed according to a similar protocol. Smoking appeared to slow healing and to favor relapses. Moderate consumption of alcohol appeared to decrease the relapse rate. In the present trial, ulcer size was associated with ulcer pain but not with ulcer healing.

Adult↗
PubMed1982

[Treatment and prevention of recurrence of duodenal ulcer with pirenzepin and cimetidine].

The effect of pirenzepine and cimetidine on healing, symptoms, and relapse rate of duodenal ulcer was studied in a placebo controlled double blind trial. With regard to symptoms, cimetidine (1 g daily) was superior at the beginning of therapy to a low dose of pirenzepine (75 mg daily) and to placebo. No significant differences in ulcer healing were found between the 3 treatment groups. The relapse rate after treatment with pirenzepine was lower than after treatment with cimetidine.

Adult↗
PubMed1982

Treatment and relapse prophylaxis of duodenal ulcer with pirenzepine and cimetidine.

The effect of pirenzepine and cimetidine on healing, symptoms and relapse rate of duodenal ulcer was studied in a placebo-controlled double-blind trial. Cimetidine (1 g daily) was superior at the beginning of therapy to a low dose of pirenzepine (75 mg daily) and placebo with regard to symptoms. No significant differences in ulcer healing were found between the 3 groups of treatment. The relapse rate after treatment with pirenzepine was lower than after treatment with cimetidine.

Adult↗
PubMed1980

Gardner's syndrome with glandular cysts of the fundic mucosa.

The present study describes a family (mother and son) with Gardner's syndrome. Aside from the classical findings, gastric polyposis was found; histologically glandular cysts of the fundic mucosa were diagnosed. The occurrence of gastric polyps in Gardner's syndrome has recently been described with increasing frequency. These lesions have various histological aspects. A number of authors have noted several cases of Gardner's syndrome with glandular cysts of the fundic mucosa, but to our knowledge this is the first case of familial occurrence.

Adult↗
PubMed1980

How often does peptic ulcer produce "typical" ulcer symptoms?

Subjective symptoms of 876 hospitalized patients who underwent upper fiber-panendoscopy were evaluated in a prospective study. Ulcer-like symptoms were defined as pain-like discomfort with a regular food-related rhythm. These symptoms indicate ulcer disease with high specificity (96%) but low sensitivity (28%). In particular old patients with second disease rarely have ulcer-like symptoms. In spite of their high specificity, however, ulcer-like symptoms are not proof of active ulceration. Patients with scars but no ulcers may also have ulcer-like symptoms.

Aged↗
PubMed1979

[Prevention of duodenal ulcer recurrence with cimetidine (author's transl)].

The effect of long-term prophylaxis of duodenal ulceration with cimetidine was tested in a double blind trial. In 20 patients treated with cimetidine there was a four-fold reduction in the relapse rate when compared with 18 placebo-treated patients. However, treatment of the acute phase of ulceration with cimetidine increased the recurrence rate more than five-fold when compared with placebo treatment. Slow healing of ulceration was followed by a two-fold incidence of recurrence when compared with rapid healing. From the results it is concluded that recurrence occurs in patients after slow healing and (or) previous cimetidine treatment if long-term prophylaxis with cimetidine is not carried out.

Adult↗
PubMed1978

[Cimetidine in the treatment of duodenal ulcer (author's transl)].

In a double-blind trial of patients with duodenal ulcer at three centres the healing rate after a four-week course of treatment (1 g cimetidine daily) was 79% (30 out of 38 patients), compared with 58% (23 out of 40 patients) on placebos. Cimetidine did not effect subjective symptoms or the need for antacids to relieve pain, except for a minor beneficial effect on diurnal ulcer symptoms during the second week of treatment. Results of long-term administration suggest that cimetidine at 400 mg daily prevent s relapses, but the possibility of an increased relapse rate after cimetidine withdrawal can not as yet be excluded.

Adult↗
PubMed1978

[Therapy of duodenal ulcer using cimetidine].

55 patients with endoscopically confirmed duodenal ulcers received either cimetidine (26 patients) or placebo (29 patients) in a double-blind trial. At four weeks, 85% of the patients treated with cimetidine and 62% of those receiving placebo had endoscopically healed ulcers. This difference is not statistically significant. However, patients on cimetidine showed a more rapid and statistically significant reduction in the size of their ulcers.

Cimetidine↗
PubMed1978

[Epidemiology of duodenal ulcer (author's transl)].

The epidemiology of peptic ulcer was investigated in 1105 endoscopy patients in a Zurich city hospital and in a random nongastroenterological hospital population. A raised susceptibility for duodenal ulcer was found in young, mainly unskilled, foreign labourers. There was no raised susceptibility in female foreign workers who also suffered less often from gastric ulcer than Swiss women. A tendency to ulceration in certain other diseases previously incriminated and in alcohol and nicotine consumers was not observed. A connection between susceptibility to ulceration and migration is assumed.

Adult↗
PubMed1978

[Controlled trials of premedication of fiberendoscopy (author's transl)].

In four controlled studies on 771 consecutive patients we tested the value of premedication before passing a fiberendoscope. Following local anaesthesia of the throat, 10 mgs of diazepam in patients less than 60 years and 5 mgs in those over 60 years quickly injected intravenously caused a sufficient premedication for fiberendoscopy. Premedication with diazepam is better than placebo. We fell that omission of premedication is not justifiable. Flunitrazepam, for premedication, in doses of 1-2 mgs did not prove to be suitable. 20 patients were radiologically controlled for signs of aspiration following premedication and endoskopy. They showed no signs of aspiration.

Adult↗
PubMed1977

Treatment of acute viral hepatitis with (+)-cyanidanol-3.

A double-blind trial of (+)-cyanidanol-3 (2 g/day) versus placebo tablets was carried out in 100 patients with acute viral hepatitis. 51 received the drug and 49 placebo. (+)-Cyanidanol-3 accelerated the disappearance of HBsAg from the blood, lowered serum-bilirubin, and relieved symptoms such as anorexia, nausea, and pruritus. The drug was well tolerated. None of the patients had a relapse of acute hepatitis. Chronic active hepatitis developed in 1 of the placebo-treated patients. Thus, (+)-cyanidanol-3 seems to be of benefit in acute viral hepatitis.

Adult↗