Proliferative patterns of rectal mucosa as predictors of advanced colonic neoplasms in routinely processed rectal biopsies

OBJECTIVES: We sought to determine whether the evaluation of rectal cell proliferation in routinely processed rectal biopsies of apparently normal mucosa can predict the presence of advanced colonic neoplasms. METHODS: Fifty consecutive patients, who did not meet any of the following exclusion criteria, underwent total colonoscopy. Patients with nonadvanced adenomas, inflammatory bowel disease, hereditary predisposition to colonic cancer, or a history of colonic neoplasms were excluded. Patients with neoplasms in the distal 40 cm of the large bowel were also excluded. An adenoma was considered advanced if it had a diameter > 1 cm, or villous or severe dysplasia histology were present. In 26 of the 50 patients (Group A: 16 men, 10 women; mean age, 65 yr) advanced colonic neoplasms (advanced adenomas or cancer) were detected; in the remaining 24 (Group B: 13 men, 11 women; mean age, 66 yr) the large bowel was free of neoplasms. In all patients the proliferative patterns of apparently normal rectal mucosa were evaluated using the monoclonal antibody MIB-1 to assess the expression of Ki-67 antigen in routinely processed tissues. Proliferation index for the entire crypt, as well as proliferation indices for each of the five equal compartments, into which the crypt had been divided longitudinally, were calculated for each patient. RESULTS: The mean proliferation indices were similar between the two groups compared. The mean proliferation index for the upper crypt compartments (4 + 5) in the Group A patients was significantly higher than for those of the Group B patients (p < 0.01). Multivariate stepwise logistic regression analysis revealed that among gender, age, and proliferative parameters, the pattern of cell proliferation in the upper rectal crypt (4 + 5) compartment was the only predictor of advanced colonic neoplasms (beta = 11.01, p < 0.001). CONCLUSIONS: Our data suggest that the evaluation of the upward expansion of the rectal crypt proliferative zone in routinely processed rectal biopsies of apparently normal mucosa appears to predict the presence of advanced colonic neoplasms. These preliminary results should be confirmed in larger studies.     

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.     

Evidence for a conjugation-like mechanism of DNA transfer in Helicobacter pylori

Many strains of Helicobacter pylori are naturally competent for transformation in vitro. Since there is a high degree of genetic variation among H. pylori strains, we sought to determine whether mechanisms of DNA exchange other than transformation exist in these organisms. Studies were done with H. pylori cells that each were resistant to two different antibiotics; the procedure used involved mating of cells on plates or in broth, in the absence or presence of DNase. In each experiment, such matings produced progeny with the markers of both parents. Examination of the full resistance profile and random arbitrarily primed DNA PCR (RAPD-PCR) profiles of the progeny indicated that DNA transfer was bidirectional. DNase treatment reduced but did not eliminate transfer; only the presence of both DNase and a membrane separating the cells did so. For progeny derived from matings in the presence of DNase, antibiotic resistance and RAPD profiles indicated that transfer was unidirectional. DNase-treated cell-free supernatants also did not transform, ruling out transduction. These experiments indicate that both a DNase-sensitive mechanism (transformation) and a DNase-resistant conjugation-like mechanism involving cell-to-cell contact may contribute to DNA transfer between H. pylori cells.     

Human antibody response to Helicobacter pylori lipopolysaccharide: presence of an immunodominant epitope in the polysaccharide chain of lipopolysaccharide

We have examined the antibody response to Helicobacter pylori lipopolysaccharides (LPS) in humans. We used sera from patients with gastroduodenal diseases and healthy adults infected or not infected with H. pylori. Data from the experiments for antibody binding to LPS suggested that the polysaccharide chains from many H. pylori strains showed high immunogenicity in humans. Sera from most (above 70%) H. pylori-infected individuals contained immunoglobulin G (IgG) antibodies against the polysaccharide region highly immunogenic H. pylori LPS. The IgG titers of individual serum samples that reacted strongly with highly immunogenic LPS were quite similar (r2 = 0.84 to 0.98). The results suggest wide distribution among H. pylori strains of a highly antigenic epitope in the polysaccharide moieties of their LPS. Also, the similarity in the titers of individual serum samples against highly immunogenic LPS points to the existence of epitopes sharing a common structural motif. However, some strains showed low antigenicity, even those with polysaccharide-carrying LPS. The dominant subclass of IgG that reacted with the highly immunogenic LPS was IgG2, which was preferentially raised against polysaccharide antigens. Recently, a structure that mimics that of the Lewis antigens was identified in the O-polysaccharide fraction of H. pylori LPS; however, no correlation between antigenicity of the polysaccharide chain in humans and the presence of Lewis antigens was found. The IgA and IgM titers against H. pylori LPS seemed to be mostly nonspecific and directed against lipid A. In a few cases, however, sera from individuals infected with H. pylori gave strong IgA and IgM titers against the highly immunogenic polysaccharide. In conclusion, the LPS of many H. pylori strains possess an antigenic epitope in their polysaccharide regions that is immunogenic in humans. However, our results show that the antigenic epitope is unlikely to be immunologically related to structures mimicking Lewis antigens.     

Antibody to a Helicobacter pylori species specific antigen in patients with adenocarcinoma of the stomach

This study attempted to identify a possible antibody response to Helicobacter pylori, which is associated with patients with adeno-carcinoma of the stomach. By using proteins of H. pylori as the antigen, pooled sera from gastric cancer and non-cancer patients were used as the first antibody for Western blot analysis. Antibody responses to a 26 kD secreted protein were observed in pooled cancer sera, but not in pooled sera from non-cancer patients. The protein was purified, while amino acid sequences revealed that it was a H. pylori species specific protein. The gene of this protein was cloned and a recombinant protein was expressed in E. coli. In addition, an antibody to the recombinant protein was tested in each individual patient using Western blot analysis. None of the forty non-gastric cancer patients were positive for the antibody to the recombinantly expressed 26 kD species specific protein. Meanwhile, six of the twenty four cancer patients tested positive (0/40 vs 6/24, p < 0.01). Results presented herein demonstrate that the species specific protein of H. pylori can be useful in detecting H. pylori associated with adenocarcinoma of the stomach.     

Circulating immunoglobulin G1 antibody in patients with ulcerative colitis against the colonic epithelial protein detected by a novel monoclonal antibody

Autoimmunity has been implicated in the pathogenesis of ulcerative colitis (UC). Several studies have shown amplified immunoglobulin G1 (IgG1) antibody response in UC; however the immunoreactive antigen(s) is unknown. To study this antigen(s), mucosal colonic extract was prepared by sonication, ultracentrifugation followed by ion exchange chromatography in fast protein liquid chromatography. The fraction (enriched colonic peptide), that was most reactive to a novel monoclonal antibody, 7E12H12 (IgM isotype), was isolated and used to examine the immunoreactivity against the patients' serum samples. Two hundred and thirteen coded samples from 111 patients with UC (symptomatic and untreated (63), symptomatic and treated (26), remission (22)); 47 with Crohn's disease (CD) (40 were symptomatic and untreated, and 30 had colonic disease); 29 with acute diarrhoea caused by specific pathogen(s); 10 with systemic lupus erythematosus, and 16 normal subjects were examined against the enriched colonic peptide by IgG subtype specific enzyme linked immunosorbent assays (ELISAs). Total IgG antibody reactivity was significantly (p < 0.01) higher only in symptomatic and untreated UC patients compared with each of the non-UC group, but the sensitivity was only 50%. IgG2 and IgG3 reactivities were not different among various groups. The IgG1 antibody reactivity against the enriched colonic peptide, however, differentiated UC patients from CD and each of the other non-UC groups. Seventy nine per cent of the patients with UC, treated or untreated, symptomatic or in remission, had significantly (p < 0.0001) higher IgG1 antibody against the enriched colonic peptide when compared with each of the other non-UC groups. Only 12% of CD serum samples and none of the other control serum samples reacted. Using purified serum IgG1 and 7E12H12-IgM, by 7E12H12 reactive peptide indeed reacts with UC-IgG1 antibody but not with control IgG1.     

Lack of a specific immune response against a recombinant capsid protein of Jaagsiekte sheep retrovirus in sheep and goats naturally affected by enzootic nasal tumour or sheep pulmonary adenomatosis

Enzootic nasal tumour (ENT) and sheep pulmonary adenomatosis (SPA) are two contagious adenocarcinomas of the respiratory tract of sheep and goats. Both diseases are associated with related, but distinct, type-D-retroviruses (ENTV and JSRV respectively). No evidence of circulating antibodies has been described in animals affected by either ENT or SPA using antigens from natural sources. We evaluated the usefulness of a recombinant JSRV capsid protein (JSRV-CA) as antigen to study the antibody responses of animals naturally affected by ENT or SPA, using immunoblotting. Positive reactions were detected in the sera of both affected and unaffected sheep and goats. The reactivity was abolished completely by absorption with the GST fusion partner but not by JSRV-CA, suggesting that it was not specific. The results support prior observations indicating that sheep and goats infected by JSRV and ENTV do not develop specific humoral responses to these retroviruses.     

Cure of autoimmune gastritis by Helicobacter pylori eradication in a 21-year-old male

BACKGROUND: More recent investigations have shown that in some patients Helicobacter pylori (Hp) antibodies can act as antigastric antibodies and lead to atrophic autoimmune gastritis of the oxyntic mucosa. The question thus arises as to whether this form of autoimmune gastritis can be healed by eradicating Hp. METHODS: Case history of a 21-year-old man with active autoimmune gastritis of the oxyntic mucosa with lymphocytic infiltration of the entire lamina propria, foci of lymphocytic destruction of a number of glands, and hypertrophy of the preserved parietal cells, but no signs of Hp in the Warthin Starry stain. The search for parietal cell antibodies and intrinsic factor antibodies proved negative, while the level of the gastrin in the serum was slightly elevated. Since the presence of Hp IgG antibodies (243 U/ml) was confirmed. Hp eradication therapy was carried out. RESULTS: 15 months after Hp treatment the Hp IgG antibody titre had decreased to 11 U/ml. The autoimmune gastritis had healed, and autoaggressive inflammatory infiltrates with focal destruction of corpus glands and hypertrophy of the parietal cells were no longer detectable. CONCLUSIONS: Autoimmune gastritis induced by Hp may possibly be cured with Hp eradication treatment; to confirm this, further controlled prospective studies are needed.     

Helicobacter pylori infection accelerates gene expression of glicentin in the gastric mucosa. Its association with intestinal metaplasia of the stomach

AIMS: A recent immunohistochemical analysis of the Aschoff lesions in rheumatic fever, combining immunohistochemical analysis with comparative morphology, permitted the division of the Aschoff nodules into three stages: (1) Aschoff nodule without admixed lymphocytes, (2) Aschoff nodules with a few T lymphocytes, and (3) Aschoff nodules containing many admixed lymphocytes of both B- and T-cell phenotype. It was postulated that the order of progression was from stage 1 with macrophages only, to accumulation of first T lymphocytes (stage 2) and then B lymphocytes (stage 3). This study was undertaken to determine the role and distribution of interleukin 1 (IL-1), interleukin 2 (IL-2) and tumour necrosis factor alpha (TNF alpha) in the various stages of the rheumatic Aschoff nodule to investigate our hypothesis on the progression of these nodules. METHODS AND RESULTS: Sixteen fresh valve specimens from patients with acute rheumatic fever undergoing valve surgery were obtained. Tissue sections from 14 specimens identified as containing Aschoff nodules were subjected to immunohistochemistry for (1) T and B lymphocytes, to stage the lesions according to our previously proposed criteria; (2) IL-1, IL-2 and TNF alpha; and (3) CD4 and CD8 to phenotype the T lymphocytes. The stage 1 and 2 lesions expressed IL-1 and TNF alpha in the macrophages. The stage 3 lesions showed more variable expression of all three cytokines including IL-2 within T lymphocytes. CONCLUSION: TNF alpha and IL-1 secretion in macrophages is required for T and B lymphocytes activation and aggregation; suggesting that macrophages arrive at the scene of rheumatic injury prior to the lymphocytes. IL-2 is usually expressed later in the inflammatory process and was found only in the lymphoid aggregates. This study therefore produces corroborative evidence for our previously proposed developmental stages of the Aschoff nodule.     

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.     

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.     

Construction and characterization of a Helicobacter pylori clpB mutant and role of the gene in the stress response

Antiserum raised against whole Helicobacter pylori cells identified a novel 94-kDa antigen. The nucleotide sequence of the gene encoding the 94-kDa antigen was determined, and analysis of the deduced amino acid sequence revealed structural features typical of the ClpB ATPase family of stress response proteins. An isogenic H. pylori clpB mutant showed increased sensitivity to high-temperature stress, indicating that the clpB gene product functions as a stress response protein in H. pylori.     

Detection of Helicobacter pylori in fecal samples of gnotobiotic mice infected with H. pylori by an immunomagnetic-bead separation technique

By an immunomagnetic-bead (IMB) separation technique, isolation of Helicobacter pylori from gastrointestinal and fecal samples of gnotobiotic mice infected with the microorganism was tried. The isolation rate of H. pylori from stomach samples after IMB separation was not higher than that of direct culture of the samples. After IMB separation of feces, H. pylori was detectable by PCR, although H. pylori was not culturable.     

The killing of Helicobacter pylori by low-power laser light in the presence of a photosensitiser

Activation and proliferation of human T lymphocytes in vitro can be obtained by various stimuli including specific antigens, mitogens, and cytokines. Here we describe the effect of interleukin-10, interleukin-12 and tumor necrosis factor-alpha on the interleukin-2 dependent proliferation and function of established human CD4+ and CD8+ alloreactive T-cell clones in the absence of antigen presenting cells. IL-12 and TNF-alpha both demonstrated an inhibitory effect on the proliferation of CD8+ cytotoxic T lymphocyte clones, whereas IL-10 enhanced the proliferation. IL-12-induced inhibition of CD8+ CTL clones was not mediated by the endogenous production of TNF-alpha by these clones. The strong inhibitory effect of IL-12 and TNF-alpha did not result in apoptosis. These cytokines did not alter the cytotoxicity of CD8+ CTL clones. When CD4+ T-cell clones were tested in the absence of APC, no significant change in IL-2-dependent proliferation due to IL-10, IL-12, and TNF-alpha could be measured. Since these effects on established CTL clones are in contrast to the effects of IL-10, IL-12, and TNF-alpha during the induction phase of immune responses, a dichotomy of immunomodulatory cytokines such as IL-10, IL-12, and TNF-alpha early and late in the immune response is suggested.     

Local immune response in Helicobacter pylori-infected cats and identification of H. pylori in saliva, gastric fluid and faeces

Helicobacter pylori-infected cats were screened by culture and polymerase chain reaction (PCR) for the presence of H. pylori in salivary secretions, gastric juice, gastric tissue and faeces. H. pylori was cultured from salivary secretions in six of 12 (50%) cats and from gastric fluid samples in 11 of 12 (91%) cats. A 298 base pair polymerase chain reactions (PCR) product specific for an H. pylori 26000 MW surface protein was amplified from dental plaque samples from five of 12 (42%) cats and from the faeces of four of five (80%) cats studied. Analyses of serum and mucosal secretions by enzyme-linked immunosorbent assay (ELISA) revealed an H. pylori-specific immunoglobulin G (IgG) response, and elevated IgA anti-H. pylori antibody levels in salivary and local gastric secretions. Immunohistochemical analyses of gastric tissue revealed the presence of IgM+ B cells assembled into multiple lymphoid follicles surrounded by clusters of CD4+ and CD8+ T cells. The lamina propria also contained single cells or aggregates of IgA+ and IgM+ B cells. These observations show that H. pylori can be identified in feline mucosal secretions, and that a localized IgA immune response develops in gastric tissue of H. pylori-infected cats. The findings suggest a zoonotic risk from exposure to personnel handling H. pylori-infected cats in vivaria.     

Helicobacter pylori infection and gastric cancer. A nested case-control study in a rural area of Japan

We conducted a seroepidemiological nested case-control study to determine the association of gastric cancer with Helicobacter pylori infection and atrophic gastritis. A cohort of 2858 participants in an annual multiphasic health check-up were followed for eight years. Data for 45 gastric cancer cases and 225 sex-, age-, and address-matched control subjects were analyzed. Helicobacter pylori infection was determined by IgG antibodies, and atrophic gastritis was diagnosed by both serum pepsinogen I level (< or = 70 ng/ml) and the pepsinogen I/II ratio (< or = 3.0). Univariate analysis showed that Helicobacter pylori and atrophic gastritis were significantly associated with gastric cancer. In a multivariate analysis, atrophic gastritis was associated with significantly increased risk of cancer (odds ratio, 3.38; 95% confidence interval, 1.54-7.42); however, Helicobacter pylori was not associated with cancer (odds ratio, 1.84; 95% confidence interval, 0.59-5.72). These results suggest that Helicobacter pylori infection alone is not directly associated with gastric carcinogenesis but has an indirect relation to gastric cancer through the development of atrophic gastritis.     

Relationship between local immune response to Helicobacter pylori and the diversity of disease: investigation of H. pylori-specific IgA in gastric juice

In order to evaluate the relationship between local immune response to Helicobacter pylori and the diversity of disease, 77 asymptomatic subjects who underwent a health examination were studied. Helicobacter pylori-specific IgG in serum and H. pylori-specific IgA in gastric juice were measured by ELISA, and the measured IgA titre was classified into two grades, low or high. Histological classification of gastritis was performed according to the Sydney system. Cytokines in gastric juice were also measured, and the cytotoxin-associated gene A (cagA) status of H. pylori was tested by PCR. Of the 65 subjects who were positive for H. pylori-specific IgG in serum, 38 (58.5%) were classified as H. pylori-specific IgA low titre in gastric juice and 27 (41.5%) had high titres. In the IgG-positive, IgA-low group, the rate of peptic ulcers (especially duodenal ulcers) in endoscopic findings was higher (P < 0.05); the score of activity and the density of H. pylori were higher (P < 0.001 and P < 0.05, respectively); the score of metaplasia was lower (P < 0.05); and the level of interleukin-1 beta was lower (P < 0.05) than in the IgG-positive, IgA-high group. The positive rate of the cagA gene was 84.4% and there was no significant difference between the two groups. There were differences in endoscopic and histological findings between the IgG-positive, IgA-low and the IgG-positive, IgA-high groups. It is suggested that persons infected with H. pylori can be divided into two different states of disease according to local immune response.     

Prevalence and demographic determinants of metronidazole resistance by Helicobacter pylori in a large cosmopolitan cohort of Australian dyspeptic patients

1. Heterozygous naked neck birds were raised under natural spring (average 21.2 degrees C) and summer temperatures (average 27.1 degrees C) to investigate the influence of dietary energy on broiler performance, carcase yield and nutrient composition of breast meat. 2. Birds were fed on a low energy diet of 12.12 MJ ME/kg, a medium energy diet of 12.96 MJ ME/kg and a high energy diet of 13.79 MJ ME/kg with 2 protein concentrations per energy treatment, 230 and 200 g/kg, from 0 to 3 and 3 to 7 weeks of age, respectively. 3. Summer rearing resulted in a decrease in body weight, body weight gain, carcase weight and carcase part yields of birds. 4. Increasing dietary energy from 12.12 to 13.79 MJ ME/kg increased body weight at 3 and 7 weeks, body weight gains from 0 to 3 and 3 to 7 weeks, carcase weights and relative abdominal fat weights of birds in a linear manner. There was no effect of dietary energy on the nutrient composition of breast meat. 5. It was concluded that there was no differences in dietary energy requirements of heterozygous naked neck birds when grown under natural optimum (21.2 degrees C) and summer temperatures (27.1 degrees C).     

Lactic acid-mediated suppression of Helicobacter pylori by the oral administration of Lactobacillus salivarius as a probiotic in a gnotobiotic murine model

OBJECTIVES: We examined whether or not the lactobacilli administered to treat Helicobacter pylori (H. pylori) infection can suppress the colonization of H. pylori, and we also sought to elucidate the mechanism of such suppression. METHODS: We used an in vitro culture system and an H. pylori-infected gnotobiotic murine model. RESULTS: Among the lactobacillus species examined in vitro, Lactobacillus salivarius (L. salivarius) but not L. casei or L. acidophilus proved to be capable of producing a high amount of lactic acid and thus completely inhibiting the growth of H. pylori in a mixed culture. The validity of L. salivarius as a probiotic to suppress H. pylori and thus reduce the inflammatory response was again confirmed in vivo by using an H. pylori-infected gnotobiotic murine model. CONCLUSION: Based on our findings, L. salivarius was found to be a potentially effective probiotic against H. pylori.