Partial vs full beta-receptor agonism. A clinical study of inhaled albuterol and fenoterol

To further investigate a proposed relationship between Chlamydia pneumoniae and coronary heart disease, coronary atheromas were collected from patients undergoing percutaneous atherectomy. Fifty-eight atheroma specimens were examined by culture and polymerase chain reaction (PCR) and 22 by electron microscopy. All were negative for C. pneumoniae, except a single specimen that was PCR-positive. These results differ from studies in other populations, in which this organism was identified by nonculture methods within coronary atheromas obtained at autopsy. Anti-C. pneumoniae antibody titers from 65 of the patients were compared with those of 28 asymptomatic controls. IgG titers were higher in controls than in patients. There is no evidence that C. pneumoniae exists within atheromas in this study population, nor does seroprevalence correlate with the presence of coronary disease in these patients.     

Confirmed previous infection with Chlamydia pneumoniae (TWAR) and its presence in early coronary atherosclerosis

BACKGROUND: Chlamydia pneumoniae has been identified in coronary atheroma, but concomitant serum antibody titers have been inconsistently positive and unavailable before the detection of early or advanced atherosclerotic lesions. METHODS AND RESULTS: This retrospective investigation was performed on premortem serum specimens and autopsy tissue from 60 indigenous Alaska Natives at low risk for coronary heart disease, selected by the potential availability of their stored specimens. Serum specimens were drawn a mean of 8.8 years (range, 0.7 to 26.2 years) before death, which occurred at a mean age of 34.1 years (range, 15 to 57 years), primarily from noncardiovascular causes (97%). Coronary artery tissues were independently examined histologically and, for C pneumoniae organism and DNA, by immunocytochemistry (ICC) and polymerase chain reaction (PCR) with species-specific monoclonal antibody and primers. Microimmunofluorescence detected species-specific IgG, IgA, and IgM antibody in stored serum. C pneumoniae, frequently within macrophage foam cells, was identified in coronary fibrolipid atheroma (raised lesions, Stary types II through V) in 15 subjects (25%) and early flat lesions in 7 (11%) either by PCR (14, 23%) or ICC (20, 33%). The OR for C pneumoniae in raised atheroma after a level of IgG antibody > or =1:256 >8 years earlier was 6.1 (95% CI, 1.1 to 36.6) and for all coronary tissues after adjustment for multiple potential confounding variables, including tobacco exposure, was 9.4 (95% CI, 2.6 to 33.8). CONCLUSIONS: Serological evidence for C pneumoniae infection frequently precedes both the earliest and more advanced lesions of coronary atherosclerosis that harbor this intracellular pathogen, suggesting a chronic infection and developmental role in coronary heart disease.     

A new approach to the brachial plexus: clinical results

Chlamydia pneumoniae was isolated from the pharyngeal swab of a 15-year-old patient with acute bronchitis. The serum IgM antibody against C.pneumoniae was elevated up to 160-fold in the acute phase and decreased to 20-fold in the convalescent phase using the microimmunofluorescence (MIF) test. IgG antibody titers in the acute phase and the convalescent phase were 40-fold and 160-fold respectively using the MIF test. The patient recovered from the bronchitis without any effective treatment, indicating spontaneous cure of the disease.     

Chlamydia pneumoniae and Helicobacter pylori infections in Sámi and Finnish reindeer herders

The Sámi people in northernmost Finland have lower mortality from cardiovascular diseases than the main population of Finland. Chronic infections caused by Chlamydia pneumoniae and Helicobacter pylori, both quite recently discovered gram-negative bacteria, have been associated with atherosclerosis. We studied the prevalence of these infections in Sámi and Finnish men by analysing the C. pneumoniae and H. pylori specific serum IgG and IgA antibodies using microimmune fluorescence and enzyme linked immunosorbent assay methods, respectively. The frequency of C. pneumoniae IgG antibodies and the age adjusted geometric mean titres differed significantly between these groups. The Finns were more often sero-positive than the Sámi (76% vs. 67%, respectively), the age adjusted geometric mean titre being 71.6 in the Finns and 38.3 in the Sámi; p = 0.001. No significant difference was found in the H. pylori IgG and IgA antibody prevalences, nor in the geometric mean titres between these groups. The difference in cardiovascular mortality between the Sámi and Finns may be partly explained by the lower incidence of chlamydial infections in the Sámi.     

Association of Chlamydia pneumoniae IgA antibodies with recently symptomatic asthma

To determine whether recently diagnosed adult-onset asthma is associated with serologic evidence of chronic Chlamydia pneumoniae infection, we performed a case-control study in a primary care clinic of cases with asthma (25 adults reporting first symptoms of asthma within 2 years of enrollment) and 45 concurrently enrolled sex and age (+/- 10 years) matched non-asthmatic controls with normal pulmonary function. C. pneumoniae-specific IgA, IgG and IgG4 antibodies, and circulating immune complexes (CIC) were measured by microimmunofluorescence testing. Results showed that frequencies of IgG titres > or = 16 (92%), IgG4 titres > or = 16 (20%) and CIC > or = 4 (60%) in asthma patients were not significantly different from those of controls. However, asthmatics had a significantly higher prevalence of C. pneumoniae-specific IgA titres > or = 10 (72% of cases vs 44% of controls, P < 0.05). After adjustment for the effects of age, sex and smoking, the odds ratio for an association of IgA and asthma was 3.7 (95% confidence interval 1.2-11.5). We conclude that recently symptomatic reversible airway obstruction in adults is associated with the presence of C. pneumoniae-specific IgA antibodies, a proposed indicator of chronic respiratory C. pneumoniae infection.     

Chlamydia pneumoniae and acute myocardial infarction in Jerusalem

BACKGROUND: A number of studies in European and North American populations have reported associations between Chlamydia pneumoniae seropositivity and coronary heart disease (CHD). Our objective was to assess the association of IgG and IgA antibodies to C. pneumoniae with acute myocardial infarction (MI) in a population-based case-control study in a Middle Eastern country. METHODS: Eligible cases aged 25-64 with a first acute MI were ascertained through an active surveillance system in Jerusalem hospitals between 1987 and 1989 (85% response). Controls were Jerusalem residents aged 25-64 sampled from the national population registry (83% response). Data on sociodemographic variables, CHD history and risk factors were collected by interview. Chlamydia serology, available for 93% of eligible participants, was performed by microimmunofluorescence on frozen stored samples using the TWAR antigen. Altogether, 251 male and 51 female cases, and 324 male and 162 female controls were analysed. RESULTS: Overall, high IgG titres (> or = 128) were not associated with increased risk of acute MI (Odds ratio [OR] = 0.74 for men [95% confidence interval (CI): 0.47-1.17] and 0.91 for women [95% CI: 0.43-1.94]); neither were high IgA titres (> or = 80) (OR = 1.11 for men [95% CI: 0.71-1.73] and 1.15 for women [95% CI: 0.33-4.0]). At IgG and IgA titres of > 32 and > 20 respectively there was also no relation. CONCLUSIONS: An association of C. pneumoniae seropositivity with acute MI was not confirmed in this population with a very high IgG seropositivity prevalence of 84% in males and 69% in females. However, we cannot exclude the possibility that a postulated recent outbreak obscured an association with chronic C. pneumoniae infection.     

Polymerase chain reaction amplification of Guthrie card deoxyribonucleic acid: extraction of nucleic acid from filter matrices

BACKGROUND: This study was designed to test the association of Chlamydia pneumoniae infection with asthma in a multi-racial population, after adjustments for several potential confounding variables. METHODS: Antibodies to C pneumoniae were measured by microimmunofluorescence in 123 patients with acute asthma, 1518 control subjects admitted to the same hospital with various non-cardiovascular, non-pulmonary disorders, and 46 patients with severe chronic asthma, including some with "brittle" asthma. Acute infection or reinfection was defined by titres of IgG of > or = 512 or IgM > or = 8 or a fourfold rise in IgG, and previous infection by IgG 64-256 or IgA > or = 8. Logistic regression was used to control for likely confounders, including ethnic origin, age, sex, smoking habit, steroid medication, diabetes mellitus and social deprivation, on antibody levels. RESULTS: Antibody titres consistent with acute C pneumoniae infection were found in 5.7% of patients with acute asthma and 5.7% of control patients, while 14.6% of patients with acute asthma and 12.7% of control patients had titres suggesting previous infection. These two groups did not differ significantly. However, titres suggesting previous infection were found in 34.8% of patients with severe chronic asthma: the difference between this group and the control group was statistically significant with an adjusted odds ratio of 3.99 (95% confidence interval 1.60 to 9.97). CONCLUSIONS: These data raise important questions about the previously demonstrated association of C pneumoniae infection with asthma, and suggest that future studies of this association should give particular attention to the presence or absence of a history of severe chronic asthma.     

Helicobacter pylori infection: relation with cardiovascular risk factors, ischaemic heart disease, and social class

OBJECTIVE: To determine whether Helicobacter pylori infection is associated with the development of ischaemic heart disease and whether such infection can explain the social class inequality in ischaemic heart disease. DESIGN: Cardiovascular risk factor levels, prevalence of ischaemic heart disease (Rose questionnaire angina, and/or a history of myocardial infarction), and serum antibodies to H pylori (enzyme linked immunosorbent assay) were assessed in a cross sectional population based survey. SETTING: Belfast and surrounding districts, Northern Ireland. PARTICIPANTS: 1182 men and 1198 women aged 25-64 years randomly selected from the Central Services Agency's general practitioner lists. MAIN OUTCOME MEASURES: The relation of H pylori infection with cardiovascular risk factors and ischaemic heart disease. The association of social class with ischaemic heart disease. RESULTS: Systolic and diastolic blood pressure, plasma viscosity, and total cholesterol were not associated with H pylori infection. A weak negative association existed between H pylori infection and fibrinogen (mean (SE) difference in fibrinogen between infected and uninfected individuals -0.09 (0.04) g/l, P = 0.02) and between infection in women and high density lipoprotein (HDL) cholesterol (mean (SE) difference in HDL cholesterol between infected and uninfected individuals -0.06 (0.02) mmol/l, P = 0.006). A potentially important association was demonstrated between H pylori infection and ischaemic heart disease but this did not reach statistical significance (odds ratio (95% confidence interval (CI) 1.51 (0.93 to 2.45), P = 0.1). Social class was associated with ischaemic heart disease independently of cardiovascular risk factors and H pylori infection (odds ratio, manual v non-manual (95% CI) 1.82 (1.14 to 2.91), P = 0.01). CONCLUSION: H pylori may be independently associated with the development of ischaemic heart disease but if this is so the mechanism by which this effect is exerted is not through increased concentration of plasma fibrinogen. H pylori infection does not explain the social class inequality in ischaemic heart disease which exists independently of known cardiovascular risk factors.     

Accuracy of IgG serology and other tests in confirming Helicobacter pylori eradication

BACKGROUND: In this study we assessed the accuracy of IgG serology and other tests in confirming Helicobacter pylori eradication. METHODS: The outcome of anti-H. pylori therapy was established by at least two of the following tests: rapid urease test (RUT), culture, 14C urea breath test (non-capsule or capsule UBT), and IgG serology (Orion Diagnostica Pyloriset New EIA-G). RESULTS: Successful H. pylori eradication was confirmed in 698 of 794 patients (88%). The percentage decrease in IgG antibody titre was related to the patients' pre-treatment IgG titre and time interval after treatment. A decrease in IgG titres of 40% or more confirmed H. pylori eradication with 100% specificity, whereas the sensitivity was 82%, 90%, 98%, and 98% 3, 4, 5, and 6 months after therapy, respectively. The 40% cut-off confirmed eradication 3 to 6 months after therapy in 328 of 339 patients (97%) with pre-treatment IgG titres of >700, in 36 of 45 patients (80%) with pre-treatment titres of 300-700, and in 5 of 12 patients (42%) with pretreatment titres of <300. The sensitivity and specificity of the other tests 2 months after treatment were as follows: RUT, 84% and 100%; culture, 88% and 100%; non-capsule UBT, 100% and 89%; and capsule UBT, 100% and 97%. CONCLUSION: A decrease in IgG antibody titre of 40% or more 3 to 6 months after therapy and the capsule 14C UBT at the 2-month follow-up were both highly accurate in confirming H. pylori eradication.     

Association of virulent Helicobacter pylori strains with ischemic heart disease

BACKGROUND: Previous studies have reported an association between chronic Helicobacter pylori infection and ischemic heart disease. However, it is not clear whether this association is really due to the virulence of the bacterium or is merely the result of confounding factors (in particular, age and social class). METHODS AND RESULTS: We assessed the prevalence of infection by Helicobacter pylori and by strains bearing the cytotoxin-associated gene-A (CagA), a strong virulence factor, in 88 patients with ischemic heart disease (age, 57+/-8 years; 74 men) and in 88 age- and sex-matched controls (age, 57+/-8 years; 74 men) with similar social background. Prevalence of Helicobacter infection was significantly higher in patients than in controls (62% versus 40%; P=.004), with an odds ratio of 2.8 (95% CI, 1.3 to 7.4; P<.001) adjusted for age, sex, main cardiovascular risk factors, and social class. Patients with ischemic heart disease also had a higher prevalence of CagA-positive strains (43% versus 17%; P=.0002), with an adjusted odds ratio of 3.8 (95% CI, 1.6 to 9.1; P<.001). Conversely, prevalence of CagA-negative strains was similar in patients and controls (19% versus 23%), with an adjusted odds ratio of 0.8 (95% CI, 0.4 to 1.4). CONCLUSIONS: The association between Helicobacter pylori and ischemic heart disease seems to be due to a higher prevalence of more virulent Helicobacter strains in patients. These results support the hypothesis that Helicobacter pylori may influence atherogenesis through low-grade, persistent inflammatory stimulation.     

Lack of correlation between vacuolating cytotoxin activity, cagA gene in Helicobacter pylori, and peptic ulcer disease in children

To determine the prevalence of the cagA gene and vacuolating cytotoxin in Helicobacter pylori isolates obtained from children and to characterize the relationship between cagA, cytotoxin production, and ulcerogenesis, pediatric Helicobacter pylori isolates were tested for cagA by the polymerase chain reaction and for vacuolating cytotoxin by a cell culture assay. Helicobacter pylori isolates were obtained from 33 children referred for upper gastrointestinal endoscopy. Twenty-six of these isolates were tested for cagA by the polymerase chain reaction; all 26 (100%) were positive. Of the 26 children from whom these isolates were obtained, 26 (100%) had chronic gastritis and 12 (46%) had duodenal ulcers. Nine (30%) of 30 isolates tested showed expression of vacuolating cytotoxin, only three of which came from patients with duodenal ulceration (odds ratio 0.81, 95% confidence interval 0.1-5.3). Of the 23 cagA-positive isolates tested for cytotoxin, only nine (39%) were positive. There was no association between vacuolating cytotoxin and clinical symptoms, nor was cytotoxicity associated with ulcerogenesis. In summary, the findings suggest that cagA is not a marker of duodenal ulceration or of vacuolating cytotoxin production in children referred for endoscopy.     

Prevalence of upper gastrointestinal lesions and Helicobacter pylori infection in Crohn's disease

Crohn's disease can affect the upper gut with reported variable frequency, although concurrent Helicobacter pylori infection has been reported to be low. We prospectively investigated the prevalence of esophageal, gastric, and duodenal lesions and Helicobacter pylori infection in 67 Crohn's disease, 41 ulcerative colitis patients, and 43 controls. Symptoms, esophagogastroduodenoscopy, and multiple biopsies were performed on all patients consecutively. Endoscopic lesions were found in 63% of Crohn's disease patients, with a Helicobacter pylori prevalence of 28%. Granulomas were found in three patients. Twenty-two percent of the ulcerative colitis patients had lesions, with a 29% prevalence of Helicobacter pylori infection. Half of the controls had pathological endoscopy, and Helicobacter pylori was positive in 40% of the cases. Subjective symptoms did not predict the presence of endoscopic lesions or Helicobacter pylori infection in inflammatory bowel disease patients. Chronic gastritis and duodenitis are common in Crohn's disease patients, and the majority are not associated with Helicobacter pylori infection.     

p53 expression is of independent predictive value in lymph node-negative breast carcinoma

OBJECTIVES: To compare the diagnostic accuracy of the most widely available tests for diagnosis of Helicobacter pylori infection after antibiotic treatment. METHODS: A total of 59 H. pylori-positive, duodenal ulcer patients (mean age, 40.7 +/- 11.7 yr; 40 male and 19 female) were treated for 2 wk with either amoxicillin-metronidazole (n = 36) or omeprazole-amoxicillin-tinidazole (n = 23), and after 4 wk, were tested for H. pylori infection by [14C]urea breath test (UBT), serum IgG antibody level, and multiple antral biopsies for rapid urease testing, histology, Warthin-Starry stain, and polymerase chain reaction to detect H. pylori DNA. Infection status was established by a concordance of test results. RESULTS: H. pylori was eradicated in 47 patients (80%). UBT and rapid urease testing had the best sensitivity and specificity, although not statistically different to Warthin-Starry stain and polymerase chain reaction. Serology and histology had little diagnostic value in this setting due to high proportion of false-positive results. CONCLUSIONS: Noninvasive UBT is as accurate in predicting H. pylori status after antibiotic treatment as rapid urease testing and Warthin-Starry stain. Especially for duodenal ulcer patients, UBT could be considered the gold standard to confirm eradication of H. pylori.     

The differential effects of prostaglandin E1 and nitroglycerin on regional cerebral oxygenation in anesthetized patients

OBJECTIVES: We sought to study the possible presence of Chlamydia pneumoniae in aortic valve stenosis (AVS). BACKGROUND: Inflammation and immune mechanisms are considered important for the pathogenesis of nonrheumatic AVS. All chlamydial species are able to cause heart infections, and seroepidemiologic studies have indicated an association between chronic C. pneumoniae infection and coronary artery disease. Furthermore, the organism has been demonstrated in atherosclerotic lesions. METHODS: Aortic valve specimens with varying degrees of macroscopic disease were obtained from 35 subjects--17 consecutive patients undergoing aortic valve replacement for treatment of nonrheumatic AVS and 18 age-matched subjects at autopsy. The possible presence of C. pneumoniae in aortic valves was studied by immunohistochemical analysis, polymerase chain reaction or transmission electron microscopy, or a combination of these. RESULTS: Positive immunohistochemical staining with C. pneumoniae specific antibody was found in 9 (53%) of 17 patients with advanced aortic valve disease requiring surgical treatment (group A), 8 (80%) of 10 cadavers with clearly macroscopic aortic valve pathology (group B) and 1 (12%) of 8 grossly normal cadaver control subjects (group C). Statistical significance with regard to the presence of C. pneumoniae was found when combined diseased subjects (groups A and B: total 17 of 27 subjects) were compared with group C (p = 0.018). However, when group A was compared with group C, there was only marginal statistical significance (p = 0.088). Finally, there was a strong statistical significance (p = 0.015) when groups B and C were compared. Chlamydia pneumoniae DNA was also found in three stenotic valves, and in two of the three tested valve specimens chlamydia-like particles were seen by electron microscopy. CONCLUSIONS: Chlamydia pneumoniae is frequently present in nonrheumatic AVS. Similarly, the high number of C. pneumoniae infections detected in the early lesions of "degenerative" AVS suggest that this pathogen may play an etiologic role in the development of this disease. The validity of this relation requires additional study.     

Chronic pancreatitis and neoplasia: correlation or coincidence

Renal biopsy specimens from patients with membranous nephropathy (MN) were studied using immunohistochemical labelling to clarify the aetiological significance of Helicobacter pylori antigen in this disease. Sixteen specimens were examined, from 7 male and 9 female MN patients. Renal specimens from patients with diabetic nephropathy and IgA nephropathy, and from autopsied patients without renal diseases were obtained as controls. Immunohistochemical labelling was performed using one polyclonal antibody and three monoclonal antibodies against H. pylori. Specimens from 11 of the MN patients revealed granular deposits along the glomerular capillary walls, which reacted positively with polyclonal antibody after trypsin pretreatment. None of the control specimens revealed positive labelling. The MN specimens showed no positive reaction with the primary antibody, which had been treated for immunoabsorption testing using sonicated H. pylori. We also determined H. pylori status in these MN patients histologically and/or serologically. Of the 11 patients whose glomeruli were positive for anti-H. pylori antibody, 7 were suitable for analysis, and all were regarded as positive for H. pylori infection. These results suggest that the presence of a specific antigen in the glomeruli of patients with MN and H. pylori infection may be involved in the pathogenesis of MN.     

Mycoplasma pneumoniae pneumonia in a mouse model

To investigate the pathogenesis of acute Mycoplasma pneumoniae infection, BALB/c mice were anesthetized with metofane, and M. pneumoniae was introduced intranasally on days 0, 1, and 2. Mice were sacrificed on days 0-15. A histopathologic scoring system defined inflammatory changes in the lungs on a scale of 0-26 (least to most severe). Broth cultures were positive for all nasal passage and bronchoalveolar lavage (BAL) specimens. Histopathologic scores ranged from 0 to 21. The mean log10 (cfu/mL) were 4.1-6.4 on days 1-10 and >/=1.7 on days 13-15 for nasal passage and BAL specimens. Serum polymerase chain reaction was negative. ELISA for serum IgM and immunoblots for M. pneumoniae antibody were positive in 21 (62%) of 34 and 33 (97%) of 34 infected animals, respectively, at days 8-15. ELISA for IgG antibody was negative. This mouse pneumonia model can be used to study the immunologic and therapeutic responses to acute M. pneumoniae infection.     

Depression as a risk factor for ischaemic heart disease in men: population based case-control study

OBJECTIVE: To determine the relation between depression, anxiety, and use of antidepressants and the onset of ischaemic heart disease. DESIGN: Population based case-control study. SETTING: All 5623 patients registered with one general practice. SUBJECTS: 188 male cases with ischaemic heart disease matched by age to 485 male controls without ischaemic heart disease; 139 female cases with ischaemic heart disease matched by age to 412 female controls. MAIN OUTCOME MEASURE: Adjusted odds ratios calculated by conditional logistic regression. RESULTS: The risk of ischaemic heart disease was three times higher among men with a recorded diagnosis of depression than among controls of the same age (odds ratio 3.09; 95% confidence interval 1.33 to 7.21; P=0.009). This association persisted when smoking status, diabetes, hypertension, and underprivileged area (UPA(8)) score were included in a multivariate model (adjusted 2.75; 1.13 to 6.69; P=0.03). Men with depression within the preceding 10 years were three times more likely to develop ischaemic heart disease than were the controls (3.13; 1.27 to 7.70; P=0.01). Men with ischaemic heart disease had a higher risk of subsequent depression [corrected] than men without ischaemic heart disease (adjusted 2.34; 1.34 to 4.10; P=0.003). Depression was not a risk factor for ischaemic heart disease in women on multivariate analysis (adjusted 1.34; 0.70 to 2.56; P=0.38). Anxiety and subsequent ischaemic heart disease were not significantly associated in men or women. CONCLUSION: Depression may be an independent risk factor for ischaemic heart disease in men, but not in women.     

Skull base aspergillosis granuloma originating from the sphenoid sinus: a case report

To clarify the prevalence of Helicobacter pylori infection in enlarged fold gastritis, serum immunoglobulin (Ig) G antibody to H pylori was determined in 19 patients with severely enlarged gastric body folds (the widest fold greater than 10 mm on the radiograph), 55 patients with moderately enlarged folds (6 to 10 mm) and 44 control subjects (5 mm or less). The prevalence of serum IgG antibody to H pylori in the severe (100%) and moderate groups (100%) was significantly higher than that in controls (34.1%) (P < 0.01). There were significant differences among the three groups in serum gastrin, pepsinogen I and pepsinogen II levels (severe had the highest levels, followed by moderate and then controls, P < 0.001). H pylori colonization in the gastric mucosa was confirmed by culture, urease test or both, and inflammation by hematoxylin and eosin stain in the 25 H pylori seropositive patients who underwent endoscopy and biopsy. Results suggest that H pylori infection is highly prevalent in enlarged fold gastritis. Further studies on enlarged fold gastritis and H pylori infection are needed.     

Parietal cells in the duodenal bulb and their relation to Helicobacter pylori infection

AIM: To investigate the prevalence, and relation to Helicobacter pylori, of parietal cells in the duodenal bulb using a monoclonal antibody directed against H+,K(+)-ATPase (HK12.18). METHODS: Twenty six patients with duodenal ulcer disease and 16 healthy controls were studied. H pylori status was determined by gastric histology and culture and by the 13C-urea breath test. Four biopsy specimens were taken from the duodenal bulb and stained with HK12.18. The presence/absence and number of parietal cells in the duodenal bulb were assessed blindly by a histopathologist. RESULTS: The overall prevalence of parietal cells in the duodenal bulb was 31% (13/42) and was similar in patients with duodenal ulcer and in controls, and in H pylori positive and negative subjects. The median (range) number of parietal cells in the duodenal bulb was 7.5 (4-20) parietal cells/subject, and was similar in all four groups. CONCLUSIONS: The prevalence of parietal cells in the duodenal bulb (31%) is notably higher than previously reported in endoscopic studies, and is in keeping with reports from studies on necropsy/operative specimens. There was no difference in the prevalence or number of parietal cells in the duodenal bulb between patients with duodenal ulcer and controls, regardless of H pylori status. These findings suggest that parietal cells in the duodenal bulb do not contribute to the pathogenesis of duodenal ulcer.