Absence of Helicobacter pylori in oral mucosal lesions

A prospective study was conducted in 26 patients with benign oral ulcers and oral carcinoma and 26 age and sex matched controls to determine the prevalence of Helicobacter pylori in oral mucosal biopsies. Oral mucosal biopsies were subjected to rapid urease test, campylobacter like organism (CLO) test, histopathological examination and bacteriological culture for demonstration of H pylori. Urease test was positive for H pylori in 3 (11.4%) out of 26 cases and CLO test in 2 (14%) out of 14 cases. On histology, H pylori was identified in 4 (15.38%) out of 26 cases. The spiral organism was universally absent in culture of both patients and controls. These pilot data negate the casual association of H pylori in oral mucosal lesions.     

Production of a monoclonal antibody against the 128 kDa (CagA) protein of Helicobacter pylori

We report a case of herpes simplex encephalitis in which the patient was repeatedly examined by magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT). The patient was a 36 year-old woman who had been transferred to our institution 6 days after the onset of symptoms with mild consciousness disturbance, nuchal rigidity, and high fever. Cerebrospinal fluid examination revealed an elevated mononuclear cell count with normal sugar concentration. Intravenous aciclovir was started 7 days after the onset of symptoms. The initial plain computed tomography (CT) scans did not reveal any abnormal findings, but contrast enhanced CT the next day showed a slight enhancement effect around the affected middle cerebral artery. Serial MRI showed the initial high intensity lesion starting on the medial cortex of the temporal lobe, then spreading to throughout the entire temporal lobe. During this period SPECT showed a marked, broad hot spot in the temporal lobe. The medial temporal lobe was high density on the CT 15 days after the onset. As the encephalitic lesion spread more laterally, the hot spot on SPECT moved laterally and then decreased in activity. Eleven weeks after the onset, the MRI showed intracerebral vacuolization of the lesion and it appeared as a wide cold spot on SPECT. The cause of the hot spot seen in the acute period was thought to be vasoparalysis of the affected area rather than breakdown of the blood-brain barrier, or impaired washout of the isotope, because the SPECT images after acetazolamide administration showed the cold spot even in the subacute phase.     

Prospects for the development of a vaccine against Helicobacter pylori

Over 50% of the world population is chronically infected by the gastric pathogen, Helicobacter pylori, which is responsible for most peptic ulcer disease and is closely associated with adenocarcinoma of the stomach. Current therapies for peptic ulcer disease include antibiotic eradication of H. pylori infection. While effective, the high cost, difficulty of patient compliance with the treatment regimens, and risks of selection for resistant strains make these therapies impractical on a large scale. Studies of the pathogenesis of H. pylori have led to the identification of bacterial antigens as candidates for inclusion in novel vaccines against this disease. Both prophylactic and therapeutic vaccination have been demonstrated in animal models of Helicobacter infection. Preclinical evaluations of several antigens are at present under way and trials of vaccination in humans are planned.     

A low rate of reinfection following effective therapy against Helicobacter pylori in a developing nation (China)

Ascorbate peroxidase (APX) is a hydrogen peroxide-scavenging peroxidase which uses ascorbate (AsA) as the specific electron donor. APX has not been isolated in mammals. Ocular tissue contains AsA at high concentrations, and we detected APX activity in bovine retinal pigment epithelium (RPE) and choroid. We purified APX from bovine RPE and choroid by four chromatographic steps. The purified APX was a monomeric hemoprotein with a molecular mass of 43 kDa. The amino acid sequence of the amino-terminal region of the purified APX showed a high degree of homology to that of plants. The primary product of the APX reaction was identified as the monodehydroascorbate radical. The APX showed high specificity for AsA as an electron donor. This is the first isolation and characterization of APX from mammals, and its role in the protection against active species of oxygen in ocular tissue is discussed.     

Gastric diffusion of antibiotics used against Helicobacter pylori

Only a few pharmacological studies have been carried out on men and guinea pigs to determine the gastric diffusion of antibiotics, which are active against Helicobacter pylori. The results of these studies have been analysed in considering the physicochemical nature, the mode of administration, the way of gastric diffusion (topic and/or systemic) and the pharmacological interactions. The correlation of these pharmacokinetic results with those obtained in clinical trials is difficult because of the heterogeneity of the pharmacological and pharmacodynamic data. The absence of a convenient and suitable animal or in vitro study model renders further standardized pharmacokinetic studies in infected man and at steady state necessary.     

Direct activity of recombinant human lactoferrin against Helicobacter pylori

We report the activity of recombinant human lactoferrin against Helicobacter pylori. Lactoferrin exerted a time- and dose-dependent action against 8 of the 13 clinical isolates of H. pylori tested in vitro. These results highlight a potential therapeutic use for lactoferrin against H.pylori infection.     

Lipopolysaccharide a virulence factor of Helicobacter pylori: effect of antiulcer agents

Following its benchmark discovery, nitric oxide (NO) is now known to play important functional roles in a variety of physiological systems. Within the vasculature, NO induces vasodilation, inhibits platelet aggregation, prevents neutrophil/platelet adhesion to endothelial cells, inhibits smooth muscle cell proliferation and migration, regulates programmed cell death (apoptosis) and maintains endothelial cell barrier function. NO generated by neurons acts as a neurotransmitter, whereas NO generated by macrophages in response to invading microbes acts as an antimicrobial agent. Because neurons, blood vessels and cells of the immune system are integral parts of the reproductive organs, and in view of the important functional role that NO plays in those systems, it is likely that NO is an important regulator of the biology and physiology of the reproductive system. Indeed, in the past 10 years, NO has established itself as a polyvalent molecule which plays a decisive role in regulating multiple functions within the female as well as the male reproductive system. This review provides an overview of the role of NO in various reproductive organs under physiological and pathological conditions.     

Vector potential of houseflies (Musca domestica) for Helicobacter pylori

The mode of transmission of Helicobacter pylori is unknown. Since viable bacteria have been shown to be excreted in feces from infected individuals and houseflies habitually develop and feed on excrement, we hypothesized that flies ingest and harbor H. pylori and, in turn, contaminate the human environment. This study examined the possible vector potential of houseflies (Musca domestica) for H. pylori. Caged houseflies were exposed to freshly grown H. pylori on agar plates. After a 6-h feeding period, the plates were removed and were replaced with sterile petri dishes containing a droplet of sterile brucella broth. At regular intervals, small numbers of houseflies were removed for microbiological and histological analysis, and the petri dishes were replaced with fresh sterile plates with fresh drops of brucella broth. The flies' bodies, the flies' dissected alimentary tracts, and excreta on the petri dishes were cultured for H. pylori, whose identity was confirmed by the urease, catalase, and oxidase reactions and Gram staining. In contrast to control flies, viable H. pylori could be isolated from external surfaces for up to 12 h and from gut and excreta for as long as 30 h after the initial feeding period. After 30 h other gram-negative bacteria overgrew the cultures of samples from all locations tested, rendering the selective culture of H. pylori colonies impossible. Histological analysis revealed Helicobacter-like organisms in the gut lumen and attached to intestinal epithelial cells. We conclude that houseflies can harbor viable H. pylori on their bodies and in their intestinal tracts. They are also able to disseminate viable H. pylori in excreta, and they may therefore present a significant reservoir and be a vector in the transmission of H. pylori.     

Characterization of a Helicobacter pylori neutrophil-activating protein

Antibody-blocking studies have demonstrated the role of CD6 in thymocyte-thymic epithelial (TE) cell adhesion. Here we report that CD6 expressed by COS cells mediates adhesion to TE cells and that this interaction is specifically blocked with an anti-CD6 monoclonal antibody (mAb) or with a mAb (J4-81) that recognized a TE cell antigen. We isolated and expressed a cDNA clone encoding this antigen and show that COS cells transfected with this cDNA bind a CD6 immunoglobulin fusion protein (CD6-Rg). This antigen, which we named ALCAM (activated leukocyte-cell adhesion molecule) because of its expression on activated leukocytes, appears to be the human homologue of the chicken neural adhesion molecule BEN/SC-1/DM-GRASP. The gene was mapped to human chromosome 3q13.1-q13.2 by fluorescence in situ hybridization of cDNA probes to metaphase chromosomes. We prepared an ALCAM-Rg fusion protein and showed that it binds to COS cell transfectants expressing CD6, demonstrating that ALCAM is a CD6 ligand. The observations that ALCAM is also expressed by activated leukocytes and that both ALCAM and CD6 are expressed in the brain suggest that ALCAM-CD6 interactions may play a role in the binding of T and B cells to activated leukocytes, as well as in interactions between cells of the nervous system.     

Inhibitory effect of somatostatin on Helicobacter pylori proliferation in vitro

BACKGROUND & AIMS: Somatostatin regulates gastric function and cell proliferation. We investigated whether exogenous somatostatin modulates Helicobacter pylori proliferation in vitro. METHODS: Bacteria were cultured in 5 mL Brucella broth. Bacterial numbers of H. pylori (ATCC 43504) and Escherichia coli were calculated 48 and 5 hours after incubation, respectively, by counting the colonies on the blood agar. Chemicals were dissolved in absolute methanol and added to the broth at a final methanol concentration of 1%. Intrabacterial guanosine 3',5'-cyclic monophosphate (cGMP) and adenosine 3',5'-cyclic monophosphate (cAMP) levels were measured by radioimmunoassay. RESULTS: Somatostatin significantly suppressed H. pylori proliferation at levels at or above 10(-11) mol/L. A similar antiproliferative effect was observed with 8-bromo-cGMP. At concentrations at or above 10(-8) mol/L, dibutyryl cAMP slightly but significantly stimulated bacterial proliferation. Gastrin had no effect. Somatostatin antibody immunoglobulin G fraction blocked the antiproliferative effect of somatostatin on ATCC 43504. Scatchard plot showed that ATCC 43504 has one class of binding site with relatively high affinity (Kd, 0.31 nmol/L). Somatostatin at 10(-11) mol/L increased cGMP and cAMP in H. pylori 11-fold and 6-fold, respectively. In contrast, somatostatin neither bound E. coli nor affected its proliferation. CONCLUSIONS: Somatostatin, at a similar level in human gastric juice (approximately 10(-11) mol/L), suppresses H. pylori proliferation mediated in part by a cGMP-dependent pathway in vitro, indicating a possible inhibitory effect of somatostatin in the gastric lumen on H. pylori proliferation in humans.     

Helicobacter pylori: pretherapeutic resistance status in Germany (Ruhr area)

The hung up shoulder, or anterior subluxation locking in abduction, is a bizarre clinical picture which is not frequently seen. It is probably due to the fact that, in the subluxed position, the subscapularis muscle becomes an abductor, rather than an internal rotator. External rotation might shift the subscapular muscle fibres towards the proximal aspect of the humeral head, while joint laxity favors subluxation. It is possible that the hung up shoulder is just one aspect of multidirectional shoulder instability, given the tendency to generalised joint laxity, the frequent autoreduction, the positive sulcus sign, and initiation of subluxation by either abduction-external rotation or extension. In this series three out of four patients were treated conservatively and performed well in daily life; however, only the fourth patient had almost unlimited access to sports, thanks to surgical stabilization.     

Gastroduodenal inflammation associated with Helicobacter pylori infection. Diagnostic and therapeutic implications (a review)

Site-directed mutagenesis has proved an effective experimental technique to investigate catalytic mechanisms and to determine relations between enzyme structure and function. This article invokes an analytical model based on evolution by mutation and natural selection-Nature's analogue of site-directed mutagenesis-to derive a set of general rules relating enzyme structure and activity. The catalysts are described in terms of the structural parameters, rigidity and flexibility, and the functional variables, reaction rate and substrate specificity. The evolutionary model predicts the following structure-activity relations: (a) rigid enzyme-flexible substrate: large variation in reaction rates, broad substrate specificity; (b) rigid enzyme-rigid substrate: diffusion controlled rates, absolute specificity; (c) flexible enzyme-rigid substrate: intermediate reaction rates, group specificity; (d) flexible enzyme-flexible substrate: slow rates, absolute specificity. Spectroscopic methods and X-ray crystallography now yield important characteristics of enzyme-substrate complexes such as molecular flexibility. The evolutionary analysis we have exploited provides general principles for inferring catalytic activity from structural studies of enzyme-substrate complexes.     

Immunochemical properties of a 60 kDa cell surface-associated heat shock-protein (Hsp60) from Helicobacter pylori

Western blot analysis (immunoblotting) of cell surface-associated proteins from Helicobacter pylori confirmed our previous findings that binding of human IgG is a common property (among H. pylori strains). Purification of the IgG-binding proteins (IGBP) was achieved by two purification steps, affinity chromatography on IgG-Sepharose and nickel chelate affinity chromatography. SDS-PAGE and immunoblotting analysis revealed a 60 kDa protein with affinity for peroxidase labeled human IgG. Solid phase binding assays showed that IgG binds to an immobilized protein (IGBP). The 60 kDa IGBP binds human IgG1, IgG3 and IgM. Binding could be inhibited by the kappa chain of the human IgG, but not with its Fc fragment, nor with IgA or IgM. In addition, rabbit polyclonal antibodies raised against the 60 kDa IGBP blocked IgG binding. Monoclonal antibodies, specific to the Hsp60 heat shock protein of H. pylori recognized the 60 kDa IGBP as revealed by immunoblotting analysis, both in crude preparations and in the purified fractions.     

Glycosulfatase activity of Helicobacter pylori towards gastric sulfomucin: effect of nitecapone

The amino acid sequence of this neuropeptide was elucidated by means of a combined approach of enzymatic digestions, manual and automatic Edman degradations, and mass spectrometry. It is a 72 residue peptide (molecular mass 8388 Da), with six cysteines forming three disulfide bridges connecting residues 7-43, 23-39, and 26-52, with blocked N- and C-termini, and lacking the amino acids histidine, methionine, and tryptophan. The CHH-I of Procambarus bouvieri is compared with the other known CHHs from Orconectes limosus (98.6% identity), Homarus americanus isomorph A (83.3% identity), Homarus americanus isomorph B (79.2% identity), and Carcinus maenas (61.1% identity).     

Noninvasive diagnosis of Helicobacter pylori infection: a review

Because glial cells have been characterized by electrophysiological studies as being silent and inactive, neuroscientists have overlooked the roles of these cells in the dynamic function of the central nervous system. Recent measurements of intracellular Ca2+ concentration, however, revealed the dynamic and active features of the glial cells. Some populations of these cells gave rise to increase in intracellular Ca2+ concentration by stimulation with neurotransmitters such as glutamate, acetylcholine, serotonin, noradrenaline and histamine through the activation of specific neurotransmitter receptors distributed on the glial cells. Although the roles of the increased intracellular Ca2+ concentration in glial cells have not been elucidated, these properties suggested the functional participation of glial cells in synaptic modulation and plasticity.     

Suggestion against an oral-oral route of transmission for Helicobacter pylori infection: a seroepidemiological study in a rural area

In this study the seroepidemiology of H. pylori and Epstein-Barr virus was compared in the same setting. A sample of 705 subjects completed a structured questionnaire. A serum sample was drawn from each subject and assayed for H. pylori IgG. Antibodies to Epstein-Barr virus were determined in a subgroup of 466 subjects. Cross-tabulation of data showed that 274 (58.8%) subjects were seropositive and 20 (4.3%) were seronegative for both infections, 17 (3.6%) were seropositive for H. pylori, and 155 (33.3%) were seropositive for Epstein-Barr virus (odds ratio=2.08, 95% confidence interval: 1.008-4.3). Nevertheless, the agreement between H. pylori and Epstein-Barr virus seropositivity was no better than chance (kappa=0.067) and the age-related seroprevalence curve of Epstein-Barr virus was similar in H. pylori seropositive and seronegative subjects. Furthermore, multiple logistic regression analysis did not show any risk factor shared by both infections. The findings of this study do not support the hypothesis that H. pylori and Epstein-Barr virus share a common mode of transmission. It can be speculated that the oral cavity may not be an important reservoir for H. pylori.     

Cat owners'' risk of acquiring a Helicobacter pylori infection

OBJECTIVES/STUDY DESIGN: A random survey of equal proportions of urban and rural North Carolina general dentists was conducted to assess their knowledge and adoption of radiographic quality assurance guidelines of the American Dental Association. RESULTS: A total of 159 surveys were returned representing a response rate of 51%. A majority of respondents answered "don't know" to questions dealing with intraoral and panoramic radiography units and darkroom monitoring. Higher levels of knowledge (58% to 77%) and adoption (63% to 86%) of guidelines were seen with film-processing activities. Linear regression demonstrated substantial positive association between knowledge and adoption of guidelines (R = 0.50). Stepwise multiple regression revealed positive associations of the demographic variables of years in practice, urban location, and age with greater knowledge of guidelines (R2 = 0.33, p < 0.05). Urban location was associated with increased likelihood of adoption of guidelines (R2 = 0.09, p < 0.05).