Eapen Thomas

A newly developed PCR assay of H. pylori in gastric biopsy, saliva, and feces. Evidence of high prevalence of H. pylori in saliva supports oral transmission.

We have recently developed a new PCR assay for the detection of H. pylori. In this study, the polymerase chain reaction (PCR) assay was used to detect H. pylori in 88 gastric biopsy, 85 saliva, and 71 fecal specimens from 88 patients. H. pylori infection was confirmed in 71 of 88 patients by culture and/or histological stain of gastric biopsies. Serum IgG antibody to H. pylori was also measured and resulted in 97% sensitivity and 94% specificity. H. pylori DNA was detected by the PCR assay in gastric biopsy specimens from all 71 patients (100% sensitivity) with proven gastric H. pylori infection but not from 17 noninfected patients (100% specificity). In saliva specimens, H. pylori DNA was identified in 57 of the 68 patients (84%) with proven gastric H. pylori infection and in three of the 17 patients without gastric H. pylori infection. However, the PCR assay was only able to detect H. pylori DNA in the feces from 15 of 61 patients (25%) with proven gastric H. pylori infection and one of the 10 patients without gastric H. pylori infection. The results show that the PCR assay is reliable for detecting the presence of H. pylori in gastric biopsy and saliva specimens. The data indicate that H. pylori exists in a higher prevalence in saliva than feces and that the fecal-oral route may be an important means of transmission of this infection in developing countries but not as significant as previously suspected in the developed countries. It is likely that the oral-oral route is more prominent.

Pharmacobezoar: An Evolving New Entity

Pharmacobezoars, bezoars comprised of medications, are unusual entities. Medications reported to cause bezoars include aluminum hydroxide gel, enteric-coated aspirin, sucralfate, guar gum, cholestyramine, enteral feeding formulas, psyllium preparations, nifedipine XL, and meprobamate. They most often occur, as do bezoars of any type, in a background of altered motility or anatomy of the gastrointestinal tract. Bowel hypoactivity, dehydration, and concomitant use of anticholinergics and narcotis appear to contribute to the propensity for bezoar formation by aluminum hydroxide gel and Isocal. The hygroscopic properties of psyllium and guar gum appear to contribute to their propensity to form bezoars. Insolubility of the carrying vehicle of enteric-coated aspirin and nifedipine is the setting in which these medications form bezoars. In contrast to nonmedication bezoars, pharmacobezoars may produce additional symptoms, those related to the release of their active ingredients. In patients with suspected gastrointestinal tract emptying problems, whether esophageal, gastric, small bowel, or colonic, the astute clinician should consider pharmacobezoar in the differential diagnosis.

Helicobacter pylori Infection and Oncogene Expressions in Gastric Carcinoma and Its Precursor Lesions

Although it is fairly well accepted that Helicobacter pylori infection plays a significant role in causing gastric cancer, the exact mechanisms involved in its pathogenesis are unclear. We have examined the relationship between H. pylori infection and oncogene expression in different stages of disease progression from precursor lesions to gastric carcinoma. We used Diff-Quik stain to diagnose H. pylori infection and immunohistochemical stains against c-erbB-2, p53, ras, c-myc, and bcl-2 to determine expression of oncogenes. H. pylori infection was found in all cases of chronic gastritis, atrophic gastritis, intestinal metaplasia, and early gastric carcinoma, and in 16 of 30 (53%) cases of advanced gastric carcinoma. Overexpression of c-erbB-2 was found in 2 (7%) cases of advanced gastric carcinoma, which were H. pylori negative. Suppressor gene, p53, was overexpressed in 3 (30%) cases of intestinal metaplasia, 2 (33%) cases of early gastric carcinoma, and 18 (60%) cases of advanced gastric carcinoma. Of these 18 p53-positive advanced gastric cancer cases, 11 (61%) were H. pylori positive. Expression of ras p21 was found in 4 (40%) cases of H. pylori-negative normal mucosa, 10 (100%) cases of chronic gastritis, 1 (10%) case of atrophic mucosa, 6 (60%) cases of intestinal metaplasia, 2 (33%) cases of nonneoplastic mucosa adjacent to early gastric carcinoma, and 7 (23%) nonneoplastic mucosa adjacent to advanced gastric carcinoma, all of which showed H. pylori. No evidence of expression of either c-myc or bcl-2 was detected in any of the above-mentioned samples. The data suggest that H. pylori infection may increase expression of ras p21 proteins and induce p53 suppressor gene mutation early in the process of gastric carcinogenesis.

Risk factors for pneumonia after percutaneous endoscopic gastrostomy.

Percutaneous endoscopic gastrostomy (PEG) is currently a popular method of administering enteral feeding. Most of these patients are elderly, debilitated, and chronically ill. They are on a number of medications and have multiple diseases. With impaired consciousness and swallowing disability, these patients are prone to develop pneumonia. In order to identify possible risk factors, we followed 24 men who underwent PEG for the occurrence of pneumonia or until they died. We then analyzed the medical records of these patients for potential risk factors for pneumonia. The presence of esophagitis during PEG placement endoscopy and history of pneumonia prior to PEG were significant risk factors. Advanced age and cerebrovascular accident (CVA) tended to indicate a higher risk of pneumonia. Taking these risk factors into consideration may be beneficial in the management of such patients.

Comparison of cytotoxin genotypes of Helicobacter pylori in stomach and saliva.

We have previously reported a high prevalence of H. pylori DNA in saliva. In this study, the cytotoxin genotypes of H. pylori strains from both stomach and saliva were compared in 31 patients with gastritis and peptic ulcer. The cagA, vacA m1, vacA m2, and vacA s1 genotypes were analyzed by PCR. The 417 bp PCR products from three patients were also subjected to DNA sequencing analysis. There was 95% agreement between stomach H. pylori isolates and their corresponding saliva DNA in at least one cytotoxin genotype; 86% agreement with two cytotoxin genotypes; 59% agreement with three cytotoxin genotypes; and 27% agreement with all four cytotoxin genotypes studied. DNA sequencing from three patients showed 78.0%, 64.0%, and 66.9% homology of H. pylori from both sources, respectively. The data suggest that more than one H. pylori strain may exist in the stomach and saliva in the same patient.

Prevalence of gastroesophageal reflux in patients who develop pneumonia following percutaneous endoscopic gastrostomy: A 24-hour pH monitoring study

Percutaneous endoscopic placement of feeding gastrostomies (PEG) was pioneered by Gauderer et. al. in 1980 [1]. Since then, it has become the preferred method of providing enteral nutritional support in children and adults because of advantages in morbidity and cost [2,3]. Pneumonia is a known sequel of this procedure, occurring at different rates, depending on the length of follow-up. Some series have shown an incidence of 10% at 30 days and others 56% at 11 months [4,5]. It does not appear that PEG feeding offers an advantage over the more traditional naso-enteric tube feeding methods in this respect. To study the prevalence of gastroesophageal reflux (GER) in PEG-fed patients, we quantitated GER by 24-hour intraesophageal pH monitoring in a group of patients who developed post-PEG pneumonia and compared it with a control group. Our study demonstrates an increased prevalence of GER in the pneumonia group compared with the control group. However, the exact contribution of this observed increased GER to the development of pneumonia needs to be determined.

Efficacy of sucralfate in the prevention of recurrence of duodenal ulcers.

Eighty-four patients who were endoscopically confirmed to have healed duodenal ulcers were entered into this 1-year, double-blind, placebo-controlled trial of sucralfate, 1g twice daily, in the prevention of duodenal ulcer recurrence. Patients remained in the study until recurrence of ulceration was endoscopically confirmed. Sixty-one patients could be evaluated for efficacy of treatment. Within 6 months, 23 of 31 placebo patients (74%) and 6 of 30 sucralfate patients (20%) had ulcer recurrence. At 12 months, 25 of 31 placebo patients (80%) and 8 of 30 receiving sucralfate (27%) had ulcer recurrence. The lower rate of ulcer recurrence in patients receiving sucralfate was significant (p = 0.0001). Survival curves also showed that sucralfate was significantly more effective in preventing relapse (p = 0.0001). Three patients were judged as experiencing drug-related side effects, two of which were in the placebo group. The results indicate that sucralfate is significantly more effective than placebo in the prevention of recurrence of duodenal ulcer disease.

Acute hepatitis associated with campylobacter colitis.

A patient with proven campylobacter fetus ss. jejuni acute colitis developed hepatocellular dysfunction, which paralleled the course of the colitis. Liver biopsy showed nonspecific reactive hepatitis. Other causes of acute hepatocellular damage were excluded. The patient made a complete recovery.

Spontaneous pancreatic duct-colon fistula.

A fistula between the pancreatic duct and the colon is quite rare and usually associated with such manifestations as bleeding and sepsis. We have seen a patient with such a fistula detected almost incidentally at ERCP. We report the course of this fistula and review the literature to suggest a place for conservative surgical management.

Combination of single- and double-stranded conformational polymorphism for direct discrimination of gastric Helicobacter pylori

Abstract Molecular typing of strains among the highly diverse population of Helicobacter pylori ( H. pylori ) is an important approach for both basic and clinical studies. Genomic DNAs prepared from 18 gastric biopsy specimens, 21 H. pylori clinical isolates obtained from gastric biopsy specimens, and five isolates collected from a single patient at weekly intervals, were subjected to a combined single- and double-stranded conformational polymorphism (SDSCP) assay. The results showed that 19 of 21 isolates tested were discriminated by SDSCP analysis. SDSCP analysis of five H. pylori isolates collected from the same patient at different times resulted in five identical profiles, suggesting the reproducibility of the method. When DNA preparations from 18 gastric biopsy specimens were subjected to SDSCP analysis, 18 unique profiles were generated that matched those of their corresponding cultured H. pylori isolates from each patient. For comparison, polymerase chain reaction (PCR)-based restriction fragment length polymorphism analysis yielded only nine profiles for 20 strains. The data suggest that SDSCP analysis may be an effective and reliable method for differentiation of H. pylori strains directly from gastric biopsy specimens without requiring isolation of the organisms by culture.