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Biomedical subjects

N J Bell

Publications and source records attributed to N J Bell.

9 recordsLinked to original sources
PubMed1992

Role of gastric acid suppression in the treatment of gastro-oesophageal reflux disease.

Gastro-oesophageal reflux disease is a common condition with a complex pathophysiology. Despite the spectrum of abnormalities, gastric acid has a central role in mucosal damage, and the mainstay of medical treatment is suppression of gastric acid secretion. The results of antisecretory treatment as assessed by endoscopic healing are reviewed. H2 receptor antagonists give more rapid symptom relief than placebo and can produce endoscopic improvement in 31-88% of cases depending on the severity of oesophagitis. Complete healing, however, is seen only in 27-45% of patients and these have mainly grades I-II disease. Improved healing rates can be obtained by increasing the degree of acid suppression or the length of treatment. The addition of a prokinetic agent may be beneficial. Omeprazole heals 67-92% of patients overall and although most successful in the lower grades of oesophagitis, can also heal 48-62% of patients with grade IV disease. The degree and rate of healing seem to be related to the reduction in oesophageal acid exposure and thus may correlate with the degree and duration of acid suppression over 24 hours obtained by the various treatments. The underlying pathophysiology is unchanged, however, and long term treatment may be needed to maintain remission.

Gastric Acid↗
PubMed1992

Appropriate acid suppression for the management of gastro-oesophageal reflux disease.

Gastro-oesophageal reflux disease (GORD) results from an abnormally prolonged dwell time of acidic gastric contents in the oesophagus. Although GORD is primarily a motor disorder, the injurious effects of gastric acid are central to the pathogenic process of oesophagitis, and the severity of disease correlates with the degree and duration of oesophageal acid exposure. In the majority of patients with mild disease, oesophageal acid exposure occurs predominantly during post-prandial periods. Conventional doses of H2-receptor antagonists cannot overcome the integrated stimulus to acid secretion resulting from a meal, and are thus relatively ineffective in preventing daytime, post-prandial oesophageal acid exposure. In patients with more severe grades of oesophagitis, there are abnormally high levels of nocturnal acid exposure, with the intra-oesophageal pH being less than 4.0 for 36% of the time, compared with 5% of the time in patients with mild GORD. Control of nocturnal acid secretion thus becomes increasingly important. This may be made worse by relative gastric acid hypersecretion in some patients with severe GORD. The long duration of action and effective inhibition of meal-stimulated acid secretion probably explains the superiority of omeprazole in treating GORD. Preliminary meta-analysis shows that the healing rate of erosive oesophagitis at 8 weeks by antisecretory agents is directly related to the duration of suppression of gastric acid secretion achieved over a 24-hour period (r = 0.87; p less than 0.05).

Anti-Ulcer Agents↗
PubMed1986

Bronchoscopic cryotherapy for airway strictures caused by tumors.

This study reports an application of cryosurgery for the treatment of tracheobronchial tumors. Bronchoscopic cryotherapy can be applied in patients who are not candidates for other traditional therapy. The technique utilizes a nitrous oxide cryoprobe, introduced through a rigid bronchoscope. The principal feature of this probe is to be nonrigid. The cryodestruction is controlled by an impedance metric method. The study group consisted of 27 patients ranging in age from 39 to 88 years. The most frequent diagnosis was squamous cell carcinoma (14). For malignant tumors, the objective was obtained in 13 cases out of 21. Cryotherapy successfully destroyed five benign granulomas. Four or six days after cryotherapy, bronchial biopsy specimens usually showed a necrotic substance, and tumoral tissues were entirely destroyed. The time of survival is probably extended and the quality of life bettered. Most visible tumors are now reached with a flexible cryoprobe, inserted in a flexible bronchoscope.

Adenocarcinoma↗
PubMed1978

Adults' perceptions of children's independence and other sex-role characteristics as a function of child's gender label.

Male and female college students were presented with a photograph labeled as a 5-yr.-old boy or girl and heard statements attributed to the child. They then rated the child on sex-role traits and responded to open-ended questions about the child. The primary findings involved sex of child by sex of adult interactions on ratings of independence and leadership: in both cases, same-sex children were rated higher than opposite-sex children. There was also some evidence that women having high contact with children rated the child more extremely on opposite-sex traits than did those with little contact.

Adolescent↗
PubMed1975

The ontogeny of ultrasounds in two strains of Rattus norvegicus.

The developmental course of ultrasonic signaling by neonatal rat pups (Rattus norvegicus) was monitored under varying degrees of hypothermic stress. Signal rate, peak frequency, duration, and complexity of signals were analyzed separately for two different laboratory stocks. Sprague-Dawley and Wistar/Furth. Additionally, preliminary data were obtained on maternal retrieval latencies during the 1st 4 days post-partum and compared with the emission rate of neonatal ultrasounds. On the basis of these and other data, there is evidence that mothers play an important role in mediating many early experience effects. The data suggests that rate of neonatal ultrasounds may provide an index of some aspects of rat of maturity; that there may be different periods of maximum sensitivity to external stimulation in various stocks of laboratory animals; and that differential maternal responsiveness in different stocks of laboratory animals may correlate with differences in neonatal ultrasonic calling. Implications for comparative, genetic, and developmental studies are discussed.

Age Factors↗
PubMedDate not supplied

Progress with proton pump inhibition.

The proton pump, a H+/K(+)-ATPase located on the secretory canalicular membrane of the parietal cell, forms the final pathway for gastric acid secretion. Omeprazole is concentrated in the secretory canaliculus, where it is converted to its active form, which binds covalently with the H+/K(+)-ATPase, thus inhibiting acid secretion arising from any stimulus. Meta-analysis has defined the primary determinants for peptic ulcer healing as the degree of acid suppression, the duration of suppression over 24 hours, and the length of treatment. The longer duration of acid suppression with omeprazole, particularly during the day, when food is ingested and H2-receptor antagonists are less effective, is reflected in the clinical superiority for symptom relief and ulcer healing and especially for the treatment of erosive esophagitis. Extensive clinical experience has proved omeprazole to be safe, and concerns over hypergastrinemia, ECL-cell hyperplasia, and carcinoid formation have not been substantiated in humans. Recent evidence has shown that omeprazole suppresses Helicobacter pylori and, in combination with antibiotics, can eradicate this organism in a substantial proportion of patients. This effect may result from enhancement of antibiotic bioavailability and optimizing host defense mechanisms.

Duodenal Ulcer↗