Geographical Pathology of Helicobacter pylori Infection: Is There More than One Gastritis?

Helicobacter pylori is the aetiological agent of chronic gastritis and a major causative factor in duodenal and gastric peptic ulcer disease; a strong association also exists with gastric cancer and primary gastric lymphoma. The prevalence of infection in adults ranges from less than 15% in developed countries to virtually 100% in less developed areas. If H. pylori infection alone was responsible for the development of gastritis, peptic ulcer disease, gastric carcinoma and primary gastric lymphoma, one would expect the frequency of all these conditions to parallel closely the prevalence of H. pylori infection. This is clearly not the case: therefore, genetic, environmental and cultural factors must act in concert with H. pylori to induce different outcomes of the infection.

This paper outlines the geographic approach to the study of disease and discusses the possible application of this methodology to the inquiry into the relationship between H. pylori, atrophic gastritis and gastric cancer. Preliminary results of a study showing great variation in the prevalence of intestinal metaplasia in duodenal ulcer patients from different geographic origin are presented and briefly discussed.     

Vaccine against Helicobacter pylori?

The burden of illness caused by Helicobacter pylori is considerable, and there is little doubt that a therapeutic vaccine would be very useful. However, the merits of using a prophylactic vaccine to eradicate H. pylori from the human population are debatable in light of arguments that it may act as a beneficial commensal organism for many of its human hosts. With regard to the practical side of designing vaccines against H. pylori, animal models have shown us that both therapeutic and prophylactic vaccines are feasible despite the fact that, as in human hosts, immune responses raised naturally to H. pylori cannot eradicate the infection. Many advances have been made in developing optimal vaccination protocols, and recently the first human trial of a therapeutic vaccine, which showed limited but nevertheless encouraging results, was published. However, a possibly quite serious problem is that prophylactic and perhaps also therapeutic vaccines may themselves cause disease.     

Helicobacter pylori: aggressor or innocent bystander?

Helicobacter pylori seeks gastric mucosa, whether found in the stomach, duodenum, or Barrett's esophagus. Definitive diagnosis can be secured by appropriate stains of mucosal biopsies and culture, but the rapid urease test, breath isotope studies, and serologic testing are also useful. The frequency of colonization increases with advancing age, but infection occurs earlier in underdeveloped countries. Although the reservoir is uncertain, water or food transmission seems likely. There is sufficient evidence to assign an etiologic role to the bacteria in the causation of type B antral gastritis. H. pylori is found in areas of gastric metaplasia within the duodenum and is associated with duodenitis. Although acute infection leads to hypochlorhydria, chronic colonization has little effect on acid secretion. Studies have thus far failed to establish a convincing relationship between H. pylori and nonulcer dyspepsia, although the bacteria may play a role in selected patients. H. pylori is found in association with most idiopathic gastric and duodenal ulcers, but it is unclear as to whether the bacteria plays a causative or permissive role. The organism has a predilection for intercellular spaces and the mucous layer, thus affording relative isolation from luminally active antibiotics. Monotherapy with bismuth preparations transiently eliminates the bacteria, but recolonization is rapid, probably due to regrowth of sequestered organisms. A combination of metronidazole, bismuth, and tetracycline (or amoxicillin) affords the best eradication rate, but the potential side effects of this program should be considered. The present therapy of duodenal ulcer disease is effective and without significant risk. Treatment of H. pylori should be reserved for those patients who relapse on adequate maintenance therapy. If a safe and effective antibiotic becomes available, more frequent testing and earlier treatment intervention may become more attractive. H. pylori is probably an "innocent bystander" for most patients, but the bacteria may sufficiently impair the defenses of the antral and duodenal mucosa to facilitate the development and relapse of ulcer disease in subsets of patients.     

Immunizing Children Who Fear and Resist Needles: Is It a Problem for Nurses?

BACKGROUND.  Despite increasing evidence that immunization procedures can be stressful for children, little is known about what the experience of immunizing frightened and needle-resistant children can be like for nurses.
METHOD.  This article presents findings from a qualitative research project designed to explore public health nurses' feelings toward immunizing needle-resistant children. A constructivist theoretical perspective and an action research approach framed the study. Data sources included two survey questions and audio-recorded transcribed data from three focus groups. Participants included 35 public health nurses from five different health units in one Canadian province. The data were analyzed for themes and were confirmed with participants through ongoing member checking.
RESULTS.  The following four overarching themes were identified and are used to explain and describe significant features of the immunization experience that were stressful and problematic for nurses: (a) nurses experience stress when immunizing children who fear and resist needle injection; (b) the strength of child resistance and some adult behavior creates an ethical dilemma for nurses; (c) some adult responses make immunizing difficult and unsafe; and (d) resources to help nurses cope with these situations are inconsistent.     

Helicobacter pylori infection and asthma: Is there a direct or an inverse association? A meta-analysis

AIM: To analyze the consistency of a potential involvement of the bacterium infection in the asthma disease. METHODS: A systematic literature search of the terms “Helicobacter pylori” (H. pylori) associated to “asthma” using PubMed, Scopus and the Cochrane Library Central was performed. Reference lists from published articles were also employed. Titles of these publications and their abstracts were scanned in order to eliminate duplicates and irrelevant articles. The criteria of inclusion of the studies were: Original studies; the H. pylori diagnostic method has been declared; all ranges of age have been included in our study; a definitive diagnosis of asthma has been reported. RESULTS: We selected 14 articles in which the association between the two conditions was addressed. In 7 studies the prevalence of H. pylori infection in the asthma population and in the control population was made explicit. There was heterogeneity between the studies (Cohran’s Q = 0.02). The H. pylori infection in the asthma population resulted 33.6% (518 of 1542), while in the control population resulted 37.6% (2746 of 7310) (relative risk of H. pylori infection in the asthma population = 0.87, 95%CI: 0.72-1.05, P = 0.015, random effects model). Instead, considering the more virulent strains, the majority of studies showed an inverse relationship between the prevalence of H. pylori infection and asthma. CONCLUSION: In our meta-analysis the prevalence of H. pylori infection in the asthma population resulted not statistically significant lower than in control population (P = 0.15). Instead, considering the more virulent strains, the majority of studies showed an inverse relationship between the prevalence of H. pylori infection and asthma.     

Intrastrain Differences in Helicobacter pylori: A Key Question in Mucosal Damage?

Helicobacter pylori causes persistent infection and inflammation in the human stomach, yet only a small fraction of infected people develop Illness. An important question is why this diversity exists in infection outcome. In recent years, there has been evidence of substantial phenotypic as well as genotypic diversity of H. pylori. Three different phenotypes — production of vacuolating cytotoxin, presence of cagA, and ability for strong PMN activation — appear to be linked to one another and to the propensity for a H. pylori strain to cause peptic ulcer disease. Further investigation in this field may help to define which infected people bear the highest risk for serious clinical consequences, and ultimately to define optimal vaccine candidates and strategies.     

Is Azole Resistance in Aspergillus fumigatus a Problem in Spain?

Aspergillus fumigatus complex comprises A. fumigatus and other morphologically indistinguishable cryptic species. We retrospectively studied 362 A. fumigatus complex isolates (353 samples) from 150 patients with proven or probable invasive aspergillosis or aspergilloma (2, 121, and 6 samples, respectively) admitted to the hospital from 1999 to 2011. Isolates were identified using the β-tubulin gene, and only 1 isolate per species found in each sample was selected. Antifungal susceptibility to azoles was determined using the CLSI M38-A2 procedure. Isolates were considered resistant if they showed an MIC above the breakpoints for itraconazole, voriconazole, or posaconazole (>2, >2, or >0.5 μg/ml). Most of the samples yielded only 1 species (A. fumigatus [n = 335], A. novofumigatus [n = 4], A. lentulus [n = 3], A. viridinutans [n = 1], and Neosartorya udagawae [n = 1]). The remaining samples yielded a combination of 2 species. Most of the patients were infected by a single species (A. fumigatus [n = 143] or A. lentulus [n = 2]). The remaining 5 patients were coinfected with multiple A. fumigatus complex species, although A. fumigatus was always involved; 4 of the 5 patients were diagnosed in 2009 or later. Cryptic species were less susceptible than A. fumigatus. The frequency of resistance among A. fumigatus complex and A. fumigatus to itraconazole, voriconazole, and posaconazole was 2.5 and 0.3%, 3.1 and 0.3%, and 4.2 and 1.8%, respectively, in the per-isolate analysis and 1.3 and 0.7%, 2.6 and 0.7%, and 6 and 4% in the per-patient analysis. Only 1 of the 6 A. fumigatus isolates in which the cyp51A gene was sequenced had a mutation at position G448. The proportion of patients infected by azole-resistant A. fumigatus isolates was low.     

Helicobacter pylori in Peptic Ulcer: Have Koch's Postulates Been Fulfilled?

This brief review considers whether or not Koch's postulates have been fulfilled for Helicobacter pylori and peptic ulceration. The histological features of peptic ulcer disease in man are active chronic gastritis with antral predominance, duodenal gastric metaplasia and active duodenitis. Other features are hyperpepsinogenaemia, relative postprandial hypergastrinaemia and basal acid hypersecretion. The macroscopic features are duodenal bulb ulceration or lesser curve and antral gastric ulceration.

At present, gastric colonization with H. pylori has been produced in small animal species (rats and mice), but the infection is difficult to establish in immunocompetent animals, and histological gastritis is unconvincing. In larger animals the germ-free pig has been the most reliable model but the gastritis tends to be chronic with little activity.

The best examples of acute infection are in three ‘self-administration’ experiments in humans. In these cases acute gastritis with hypochlorhydria developed which, when it converted to active chronic gastritis, tended to be asymptomatic. Either the circumstances were incompatible with ulceration, or the experiments were not continued for the many years necessary to develop peptic ulceration. It is concluded that only one of the many steps required for the development of peptic ulceration has so far been fulfilled, i.e. the ability of H. pylori to produce histological gastritis in a susceptible host.     

Health promotion in nurses: Is there a healthy nurse in the house?

The purpose of this pilot study was to examine the health-promoting lifestyle behaviors of acute-care nurses using the Health Promotion Model. Statistical analysis of 149 returned Health-Promoting Lifestyle Profile II surveys indicates areas of weakness in stress management and physical activity. No significant difference is found between unit, demographic factors, and subscale scores at the p < .01 level, but medical–surgical nurses consistently scored better than the critical-care nurses in health promotion. Findings support the need for the development of holistic nursing interventions to promote self-care in the identified areas. Strategies include educational/experiential classes in holistic nursing; individualized unit-based activities fostering stress management, such as massage, reflexology, and imagery; and development of an employee wellness program.