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Biomedical subjects

J H Baron

Publications and source records attributed to J H Baron.

At least 37 records · Page 2Linked to original sources

Treatments of peptic ulcer.

From the late 19th century, Mount Sinai gastroenterologists declared their scepticism of the efficacy of all recommended treatments of peptic ulcer, and looked forward to trials which could distinguish between sequence and consequence, between association and causation. The rationale of all the early studies was to reduce gastric acidity, but it soon became clear that any neutralization by single doses of antacids was brief and ineffective. Winkelstein s demonstration that patients with duodenal ulcer had higher acidities not only before and after meals but also through the night hours led him to introduce a new treatment, the alkalinized intragastric milk drip together with atropine. One of the earliest controlled clinical trials at Mount Sinai compared different antacid regimes and showed that pH values above 3.5 were achieved in only about half of the patients on the various drips. When the new anticholinergic drugs were developed in the 1950s, they were found to produce sustained hypoacidity and were tried as maintenance treatment, as an alternative to acid-lowering operations. The third Mount Sinai approach was to attack the machinery of the acid-producing cell itself by an inhibitor of the enzyme producing hydrogen ions. In 1939, this enzyme had been thought to be carbonic anhydrase, but when Janowitz and Hollander tested its inhibitor, acetazolamide, and showed marked but very brief acid inhibition, they concluded that its action was too brief to be therapeutically useful. The problem was to be solved decades later by H2 receptor blockers from Britain and H+K+ATPase inhibitors from Sweden.

Antacids↗

The pancreas.

Pancreatic secretion was first studied at The Mount Sinai Hospital by Crohn in 1912, but measurements of pancreatic enzymes in duodenal aspirate or feces were found unhelpful in diagnosis. Such pancreatic tests fell into disuse because of advances in radiology of the biliary tree in the 1920s. Once extracts of secretin and cholecystokinin-pancreozymin became available from Sweden in the 1930s, it became possible for the biochemist Franklin Hollander and the surgeon David Dreiling to develop pancreatic secretion tests into practical procedures for the diagnosis of benign and malignant diseases of the pancreas and biliary tree, and produce physiological studies of the mechanisms of ion transport. With more purified hormones, it became possible to measure maximum (alkaline) bicarbonate output of the pancreas analogous to the maximal acid response of the stomach to an augmented histamine test, and to determine whether patients with duodenal ulcer had decreased neutralization of gastric acid in the duodenum. Clinical studies were also directed to the pathophysiology of acute relapsing and chronic pancreatitis and carcinoma. However, advances in imaging and endoscopy have now shifted the thrust of pancreatology.

Gastroenterology↗

Inhibition of platelet thrombosis using an activated protein C-loaded stent: in vitro and in vivo results.

In high-risk and complicated coronary intervention, the risk of acute closure is unpredictable. Thrombus and platelet deposition at the intervention site may also have further effects on subsequent restenosis. In vivo infusion of activated protein C has previously been shown to achieve potent anticoagulation without any haemostatic side effects. We now evaluated the in vitro and in vivo efficacy of polymer-coated coronary stents loaded with purified rabbit Activated Protein C (APC). By measuring 125I-fibrinogen/fibrin deposition APC-loaded stent-wires were antithrombotic compared to albumin-loaded, inhibited-APC-loaded, plain polymer-coated and stainless steel stent-wires. In a balloon injury rabbit iliac artery model, APC-loaded stents did not occlude (0/14) compared to plain stents (9/15) and BSA-loaded stents (2/4). Relative 111In-labelled platelet deposition showed a similarly significant degree of inhibition. In conclusion, APC-loading could render stents significantly less thrombotic. Whether an effective antithrombogenic stent like this effectively reduces restenosis rates warrants further evaluation.

Adsorption↗

Inflammatory bowel disease up to 1932.

Inflammatory bowel diseases have been a major interest of generations of Mount Sinai Hospital gastroenterologists. Although clinical descriptions of diarrhea with or without blood go back thousands of years, clear distinctions between enteritis and ulcerative colitis were possible only in the 19th century. At that time, many case reports were published of, in retrospect, classical regional enteritis. The term "ulcerative colitis" dates from 1888; the introduction of the electric sigmoidoscope soon after made it possible to make proper diagnosis of ulcerative colitis and distinguish it from infective dysentery, membranous mucous or catarrhal colitis, and nervous diarrhea. Doctors at The Mount Sinai Hospital adopted this diagnostic approach in the 1870s and 1880s, and were particularly interested in patients with tuberculosis-like ileocecal disease without tubercle bacilli. Articles were written by Weiner in 1914, Moschcowitz and Wilensky in 1923 and 1927, and Goldfarb and Suissman in 1931. Dr. A.A. Berg, in 1925, encouraged his assistant Leon Ginzburg to conduct a study of the inflammatory granulomatous diseases of the bowel, when Ginzburg and Gordon Oppenheimer were working in Dr. Paul Klemperer's laboratory. Initial reports came in 1927 and 1928, but Ginzburg and Oppenheimer "in conjunction with Dr. Burrill B. Crohn" presented a definitive paper, "Non-specific Granulomata of the Intestine," on May 2, 1932, to the American Gastro-Enterological Association. On May 13, 1932, Dr. Crohn presented a paper on "Terminal Ileitis" to the American Medical Association; this was published later that year with the title "Regional Ileitis: A Pathologic and Chronic Entity," under the authorship of Crohn, Ginzburg and Oppenheimer.

Europe↗

Motility of Helicobacter pylori in a viscous environment.

BACKGROUND: Patients with gastroduodenal disease produce gastric mucus of higher viscosity, and mucins that are of a smaller size, than normal. We have modelled these changes to the mucus layer in solutions of methylcellulose, and measured bacterial motility in biopsied mucus, to assess how they might influence the movements of Helicobacter pylori. METHODS: Motilities of Helicobacter pylori were measured in solutions of methylcellulose with molecular mass of 14 and 41 kDa, and in biopsied mucus with a Hobson BacTracker. Four parameters of bacterial motility were quantified: curvilinear velocity (CLV), path length, track linearity and curvature rate. RESULTS: All H. pylori were motile in methylcellulose solutions, and had optimal motilities at a viscosity of 3 cp (CLV in methylcellulose of 41 kDa, for instance, was 33 +/- 1.4 microm/s (mean +/- SEM) and the path length in methylcellulose of 41 kDa was 22.4 +/- 2 microm). At higher viscosities, mean CLVs, path lengths and curvature rates decreased, and track linearities increased in direct proportion to the increase in methylcellulose viscosity. Bacteria become non-motile at a viscosity of 50 cp in methylcellulose of 14 kDa, and at 70 cp in methylcellulose of 41 kDa. Mean CLVs, path lengths and curvature rates (but not track linearities) were greater in methylcellulose of 41 kDa than in methylcellulose of 14 kDa at each viscosity tested. Motilities of H. pylori from patients with duodenal ulcer or non-ulcer dyspepsia in methylcellulose solutions were not significantly different. H. pylori had poor motility in biopsied mucus, but became highly motile when biopsied mucus was diluted with saline. CONCLUSIONS: The viscosity-motility profiles of H. pylori in methylcellulose and the motilities of H. pylori in biopsied mucus suggest (1) that H. pylori may have poor motility in mucus at the epithelial surface, but high motility at the luminal surface of the mucus layer, and (2) that the increased mucus viscosity and decreased mucin size in patients with gastroduodenal disease act in combination to decrease H. pylori motility in vivo.

Helicobacter pylori↗

Randomised double blind controlled study of recurrence of gastric ulcer after treatment for eradication of Helicobacter pylori infection.

OBJECTIVE: To determine whether eradication of Helicobacter pylori infection reduces recurrence of benign gastric ulceration. DESIGN: Randomised, double blind, controlled study. Patients were randomised in a 1:2 ratio to either omeprazole 40 mg once daily for eight weeks or the same treatment plus amoxycillin 750 mg twice daily for weeks 7 and 8. A 12 month untreated follow up ensued. SETTING: Teaching and district general hospitals between 1991 and 1994. SUBJECTS: 107 patients with benign gastric ulcer associated with H pylori. MAIN OUTCOME MEASURES: Endoscopically confirmed relapse with gastric ulcer (analysed with life table methods), H pylori eradication, and healing of gastric ulcers (Mantel-Haenszel test). RESULTS: 172 patients were enrolled. Malignancy was diagnosed in 19; 24 were not infected with H pylori; four withdrew because of adverse events; and 18 failed to attend for start of treatment, leaving 107 patients eligible for analysis (35 omeprazole alone; 72 omeprazole plus amoxycillin). In the omeprazole/amoxycillin group 93% (67/72; 95% confidence interval 84% to 98%) of gastric ulcers healed and 83% (29/35; 66% to 94%) in the omeprazole group (P = 0.103). Eradication of H pylori was 58% (42/72; 46% to 70%) and 6% (2/35; 1% to 19%) (P < 0.001) and relapse after treatment was 22% (16/72) and 49% (17/35) (life table analysis, P < 0.001), in the two groups, respectively. The recurrence rates were 7% (3/44) after successful H pylori eradication and 48% (30/63) in those who continued to be infected (P < 0.001). CONCLUSIONS: Eradication of H pylori reduces relapse with gastric ulcer over one year. Eradication rates achieved with this regimen, however, are too low for it to be recommended for routine use.

Amoxicillin↗

Sex, gonads, sex hormones and histamine-stimulated gastric acid and serum pepsinogen.

OBJECTIVE AND DESIGN: The effects of sex, sex hormones and gonads were studied in dogs because men secrete more acid than woman and duodenal ulcer is commoner in men and remits in pregnancy and after stilboestrol. MATERIAL: Four male and 4 female greyhounds with chronic gastric fistulas were tested. METHODS: Histamine was infused i.v. 1-16 micrograms/min and plateau acid output measured in the last 30 min of each 60 min infusion. TREATMENT: The gonads were then removed and secretion retested. The orchidectomised dogs were then given stilboestrol 2 mg daily (+/-progesterone 25 mg i.m. three times a week) and the oophorectomised bitches given testosterone propionate 25 mg twice weekly i.m. and secretion again retested. RESULTS: Submaximal and maximal acid outputs (and serum pepsinogen) of dogs and bitches were similar and correlated with body weight. Gonadectomy did not alter these functions nor did hormones of the opposite sex given for 1-12 months. CONCLUSIONS: In the dog, as in the rat, and probably in man, histamine-stimulated gastric acid output is a function of body size and not of sex.

Animals↗

Recurrence of duodenal ulcer after Helicobacter pylori eradication is related to high acid output.

BACKGROUND: Helicobacter pylori eradication reduces the recurrence of duodenal ulcers. It is unclear why duodenal ulcers rarely recur in the absence of reinfection with H. pylori or NSAID treatment. METHODS: Basal, gastrin-releasing peptide- and pentagastrin-stimulated peak acid outputs in patients with ulcer relapse after H. pylori eradication were measured, and compared with patients without ulcer relapse after H. pylori eradication. RESULTS: Pentagastrin-stimulated peak acid output was significantly higher in H. pylori-positive patients with duodenal ulcers than in H. pylori-negative controls, and fell significantly after H. pylori eradication. In H. pylori-negative patients with recurrent duodenal ulcers, pentagastrin-stimulated peak acid output was significantly higher than in controls and similar to H. pylori-positive patients with duodenal ulcers. CONCLUSIONS: These findings suggest that duodenal ulcer relapse after eradication of H. pylori may be related to high pentagastrin-stimulated peak acid output. In this subset of patients with duodenal ulcers, maintenance anti-secretory treatment may be necessary to prevent relapse.

Adult↗

Hunterian peptic ulcers and Helicobacter pylori.

Gastric spiral organisms were first described in man in 1939 and identified as Helicobacter pylori causing peptic ulcers in the early 1980s. Surgical specimens of gastric resections from 1939 showed H. pylori to be present. Full-thickness sections of gastric mucosa from gastric specimens from the eighteenth-century Hunterian Collection at The Royal College of Surgeons of England were examined by histology for the presence of H. pylori. Four gastric ulcers and a section from an oesophageal varix showed remarkable preservation of the overall architecture, but surface autolysis did not allow identification of the bacteria. However, the presence of lymphoid aggregates in the Hunterian specimens suggests that H. pylori may have been present before autolysis.

Female↗

Cost effectiveness of screening for and eradication of Helicobacter pylori in management of dyspeptic patients under 45 years of age.

OBJECTIVE: To assess the cost effectiveness of screening for and eradicating Helicobacter pylori in patients under 45 years of age presenting with dyspepsia. DESIGN: A decision analytic model composed of a decision tree to represent the epidemiology of dyspepsia and a Markov process to model the outcomes of treatment. PATIENTS: Patients under the age of 45 years presenting to their general practitioner with (peptic type) dyspepsia. INTERVENTIONS: Conventional empirical treatment with healing and maintenance doses of cimetidine v eradication treatment solely in patients with confirmed peptic ulcer; and conventional empirical treatment for all dyspeptic patients compared with the use of a serology test to identify patients with H pylori, who then receive endoscopy to investigate the presence of peptic ulcer disease and, when disease is found, are given eradication treatment with a breath test to confirm successful eradication. MAIN OUTCOME MEASURES: Expected cumulative costs over a period of 10 years. The proportion of time patients spend without a recurrent ulcer. RESULTS: After receiving eradication treatment, patients with confirmed ulcer spend an average of 99% of their time free from recurrent ulcer disease compared with 95% after treatment with cimetidine. Eradication treatment costs less than that with cimetidine. When the initial cost of identifying appropriate patients to receive eradication treatment is added to the analysis, however, these cost savings take almost eight years to accrue. CONCLUSIONS: Enthusiasm for introducing testing for and eradication of H pylori for dyspeptic patients in general practice should be tempered by an awareness that cost savings may take many years to realise.

Adult↗