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H M El-Zimaity

Publications and source records attributed to H M El-Zimaity.

At least 19 recordsLinked to original sources

Review article: Mycobacterium avium subsp. paratuberculosis as one cause of Crohn's disease.

A number of theories regarding the aetiology of Crohn's disease have been proposed. Diet, infections, other unidentified environmental factors and immune disregulation, all working under the influence of a genetic predisposition, have been viewed with suspicion. Many now believe that Crohn's disease is a syndrome caused by several aetiologies. The two leading theories are the infectious and autoimmune theories. The leading infectious candidate is Mycobacterium avium subspecies paratuberculosis (Mycobacterium paratuberculosis), the causative agent of Johne's disease, an inflammatory bowel disease in a variety of mammals including cattle, sheep, deer, bison, monkeys and chimpanzees. The evidence to support M. paratuberculosis infection as a cause of Crohn's disease is mounting rapidly. Technical advances have allowed the identification and/or isolation of M. paratuberculosis from a significantly higher proportion of Crohn's disease tissues than from controls. These methodologies include: (i) improved culture techniques; (ii) development of M. paratuberculosis-specific polymerase chain reaction assays; (iii) development of a novel in situ hybridization method; (iv) efficacy of macrolide and anti-mycobacterial drug therapies; and (v) discovery of Crohn's disease-specific seroreactivity against two specific M. paratuberculosis recombinant antigens. The causal role for M. paratuberculosis in Crohn's disease and correlation of infection with specific stratification(s) of the disorder need to be investigated. The data implicating Crohn's as an autoimmune disorder may be viewed in a manner that supports the mycobacterial theory. The mycobacterial theory and the autoimmune theory are complementary; the first deals with the aetiology of the disorder, the second deals with its pathogenesis. Combined therapies directed against a mycobacterial aetiology and inflammation may be the optimal treatment of the disease.

Animals↗

Nitrofurantoin quadruple therapy for Helicobacter pylori infection: effect of metronidazole resistance.

BACKGROUND: Antibiotic resistance has increasingly been recognized as the major cause of treatment failure for Helicobacter pylori infection. New therapies for patients with metronidazole- or clarithromycin-resistant H. pylori are needed. AIM: To investigate the role of nitrofurantoin quadruple therapy for the treatment of H. pylori. METHODS: Patients with confirmed H. pylori infection received nitrofurantoin (100 mg t.d.s.), omeprazole (20 mg b.d.), Pepto-Bismol (two tablets t.d.s.), and tetracycline (500 mg t.d.s.) for 14 days. Four or more weeks after the end of therapy, outcome was assessed by repeat endoscopy with histology and culture or urea breath testing. RESULTS: Thirty patients were entered, including 25 men and five women; the mean age was 54.9 years. The most common diagnoses were duodenal ulcer (23%) and GERD (18%). The intention-to-treat cure rate was 70% (95% CI: 50.6-85%). Nitrofurantoin quadruple therapy was more effective with metronidazole-sensitive strains (88%; 15 out of 17) than with metronidazole-resistant strains (33%; three out of nine; P=0.008). Two of the treatment failures had pre-treatment isolates susceptible to metronidazole, which were resistant after therapy. CONCLUSIONS: Because nitrofurantoin quadruple therapy performed inadequately in the presence of metronidazole resistance, we conclude that nitrofurantoin is unlikely to find clinical utility for the eradication of H. pylori.

Administration, Oral↗

Detection of Mycobacterium avium subspecies paratuberculosis in Crohn's diseased tissues by in situ hybridization.

OBJECTIVES: Reports about the association between Crohn's disease (CD) and cell wall-deficient (CWD) forms of Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) are controversial. This may be due to the heterogeneous nature of CD where only about 50% of the patients show granulomatous inflammation. Detection of CWD forms of M. paratuberculosis in tissues from patients with CD would support its association with the disease. To help identify these forms in inflamed tissues, a previously developed and optimized nonradioactive in situ hybridization method was applied on well-defined tissue materials obtained from patients with CD, ulcerative colitis (UC), and controls. METHODS: Specimens from 37 patients with CD (15 with epitheloid cell granulomas and 22 without granulomas), 21 UC, and 22 noninflammatory bowel disease (IBD) patients were analyzed by the in situ hybridization method based on the digoxigenin-labeled M. paratuberculosis IS900 fragment, previously shown to be species specific. Samples were counterstained with hematoxylin and eosin to show the location of the positive signal. Positive controls made of beef cubes injected with CWD and acid-fast M. paratuberculosis and negative controls were included in each experiment to monitor for nonspecific hybridization or staining. RESULTS: Six of 15 (40%) patients with CD and granulomas showed positive signals in myofibroblasts and macrophages. Interestingly, no positive signals were observed within granulomas. Only 4.5% of 22 CD samples from patients with nongranulomatous disease, 9.5% of 21 UC, and remarkably, none of the 22 non-IBD patients were M. paratuberculosis positive. CONCLUSION: The demonstration of DNA from CWD forms of M. paratuberculosis in this limited number of CD tissues further supports and confirms previous reports of its association with the granulomatous type of the disease.

Adult↗

Cytokeratin subsets for distinguishing Barrett's esophagus from intestinal metaplasia in the cardia using endoscopic biopsy specimens.

OBJECTIVES: It has been suggested that Barrett's epithelium and intestinal metaplasia in the gastric cardia have different cyotokeratin (CK) staining patterns and that Barrett's epithelium can be distinguished by CK staining pattern. The aim of this study was to test the utility of CK staining for distinguishing Barrett's esophagus from gastric intestinal metaplasia. METHODS: Topographically mapped gastric biopsy specimens were obtained from patients without Barrett's esophagus, and esophageal biopsies were obtained from patients with long-segment Barrett's esophagus (>3 cm). Serial sections were stained with Genta or El-Zimaity triple stain, and biopsies with intestinal metaplasia were stained with antibodies against CK 4, 13, 7, and 20. RESULTS: Sections from 33 biopsies with Barrett's esophagus, 23 with intestinal metaplasia of the gastric cardia, 27 with intestinal metaplasia of the gastric body, and 33 with intestinal metaplasia of the antrum were examined. CK 4 and CK 13 stained squamous epithelium only. The proposed "diagnostic" CK Barrett's 7/20 pattern was found in only 39% of long-segment Barrett's compared to 35%, 4%, and 24% in intestinal metaplasia from the gastric cardia, body, and antrum, respectively. The criteria proposed had a sensitivity of 45% and a specificity of 65%. CONCLUSIONS: These results do not support keratin phenotyping as a tool for differentiating intestinal metaplasia originating in the cardia from intestinal metaplasia of Barrett's.

Barrett Esophagus↗

Gastric intestinal metaplasia: subtypes and natural history.

BACKGROUND: It has been suggested that the subtyping of intestinal metaplasia in the stomach is useful in stratifying patients with regard to risk of developing gastric cancer. AIM: To determine whether subtyping intestinal metaplasia provided useful information regarding the natural history of intestinal metaplasia. METHODS: The study used large cup gastric biopsy specimens from predetermined locations (gastric mapping). Follow up biopsies were obtained at one, two, and/or nine years. Biopsies with intestinal metaplasia were stained with high iron diamine/Alcian blue (HID/AB) to determine whether they expressed neutral mucins, sialomucins, or sulphomucins. RESULTS: Seventy nine patients with intestinal metaplasia were studied and characterised with regard to the most advanced subtype of intestinal metaplasia. The most severe type of intestinal metaplasia was type II in 33 patients and type III in 34 patients. Helicobacter pylori was cured in 67 patients. Follow up showed that changes in type of metaplasia (apparent regression or progression) occurred in both directions and were independent of H pylori status. For example, biopsy sites with "loss" of metaplasia at a follow up visit might have it "reappear" at a subsequent visit. During follow up, no patient developed gastric dysplasia or died from gastric cancer. CONCLUSION: HID subtyping did not provide useful information to the clinician or the pathologist. The data are consistent with the notion that the pattern, extent, and severity of atrophy with/without intestinal metaplasia is a far more important predictor of increased cancer risk than intestinal metaplasia subtype.

Adult↗

In situ hybridization method for studies of cell wall deficient M. paratuberculosis in tissue samples.

Cell wall deficient forms of mycobacteria may be important in the pathogenesis of Crohn's disease and sarcoidosis. However, no method has been available to localize this type of organisms in tissue sections. We developed an in situ hybridization method for the demonstration of Mycobacterium paratuberculosis spheroplasts (cell wall deficient forms) in paraffin embedded tissue sections.M. paratuberculosis spheroplasts were prepared by treatment with glycine and lysozyme. Pieces of beef were injected with the prepared spheroplasts. The samples were fixed in buffered formalin and paraffin embedded. A M. paratuberculosis-specific probe derived from the IS900 gene was used. Specificity was controlled by using an irrelevant probe and by hybridizing sections with spheroplasts from other bacteria. Beef samples injected with M. paratuberculosis spheroplasts were the only samples that hybridized with the probe. Beef samples containing acid-fast or spheroplast forms of M. smegmatis and M. tuberculosis as well as the acid-fast forms of M. paratuberculosis did not hybridize with the probe. Unrelated bacterial controls, i.e. Helicobacter pylori and Escherichia coli were also negative in the assay. In situ hybridization with the IS900 probe provides a specific way to localize M. paratuberculosis spheroplasts in tissue sections and may be useful for studies of the connection between M. paratuberculosis and Crohn's disease and sarcoidosis. The assay may also be valuable for studies on Johne's diseased animals.

Animals↗

Identification of cell wall deficient forms of M. avium subsp. paratuberculosis in paraffin embedded tissues from animals with Johne's disease by in situ hybridization.

M. avium subsp. paratuberculosis (M. paratuberculosis) is the causative agent of Johne's disease (JD) in ruminants leading to enormous economical losses in dairy and meat industries worldwide. During the subclinical stage of the disease, the infected animals are difficult if not impossible to detect by the available diagnostic tests including the PCR based ones. Although only considered an animal pathogen, cell wall deficient (CWD) forms of M. paratuberculosis have been isolated from patients with sarcoidosis and Crohn's disease (idiopathic diseases) in humans. Hence, the CWD form of this organism has been suspected to play a role in the pathogenesis of these diseases by persisting in the affected tissues and triggering a localized immune response and pathology. Differentiating between the CWD and acid-fast forms of this organism may lead to the determination of whether the CWD form is the pathogenic form in the subclinical cases of JD in animals and/or the etiologic agent for the above human diseases. To localize such organisms in tissue sections, CWD forms of mycobacteria were prepared in vitro and injected into beef cubes which were then formalin fixed and paraffin embedded. An in situ hybridization (ISH) technique, combined with the IS900 M. paratuberculosis-specific probe labeled with digoxigenin, was developed for the detection of nucleic acids specifically from the CWD forms but not their acid-fast forms in tissue sections. Specificity was confirmed by the negative finding with an irrelevant probe and with control tissue preparations containing CWD cells of related mycobacteria and unrelated organisms. This ISH procedure provides a way to distinguish between the acid-fast and CWD forms of M. paratuberculosis and to localize them in tissue sections. ISH may prove useful to evaluate the significance of CWD forms of M. paratuberculosis in the pathogenesis of JD, Crohn's disease and sarcoidosis.

Animals↗

Furazolidone combination therapies for Helicobacter pylori infection in the United States.

BACKGROUND: Antibiotic resistance has begun to impair the ability to cure Helicobacter pylori infection. AIM: To evaluate furazolidone as a component of combination therapies for treatment of H. pylori infection in the United States. METHODS: Patients with active H. pylori infection received furazolidone combination therapy for 14 days (furazolidone 100 mg and tetracycline 500 mg t.d.s.; omeprazole 20 mg o.d. in the morning and, depending on the pre-treatment antimicrobial susceptibility pattern, 500 mg of metronidazole or clarithromycin t.d.s.). RESULTS: A total of 27 patients received the metronidazole containing combination (cure rate 100%) and seven received the clarithromycin combination (cure rate 86%). Overall the cure rates for intention-to-treat was 97% (95% CI: 85% to 100%). The single failure took the clarithromycin containing combination for only 2 days (per protocol cure rate = 100%). Side-effects were common and led to discontinuation of therapy in 26% of patients. An attempt to eliminate metronidazole and clarithromycin and use furazolidone, tetracycline, and lansoprazole b.d. produced an unsatisfactory cure rate of 72%. CONCLUSION: Furazolidone combination therapy appears to be effective. Additional studies with different antimicrobial combinations and duration of therapy are warranted.

Anti-Ulcer Agents↗

Metronidazole containing quadruple therapy for infection with metronidazole resistant Helicobacter pylori: a prospective study.

BACKGROUND: Metronidazole remains a key component of H. pylori infection therapy. It has been suggested that despite resistance, metronidazole may be effective when given at high dose with bismuth, tetracycline, and a proton pump inhibitor (quadruple therapy). AIM: To prospectively evaluate metronidazole quadruple therapy for treatment of metronidazole resistant H. pylori infection in the United States. METHODS: Patients infected with metronidazole resistant H. pylori were prospectively prescribed 14 days of quadruple therapy consisting of metronidazole 500 mg t.d.s., tetracycline 500 mg q.d.s., two bismuth subsalicylate tablets q.d.s., and omeprazole 20 mg o.d. RESULTS: A total of 26 patients were entered into the study; 22 for their first treatment and four as re-treatment for failed therapy. Of the 26 patients, 24 were cured (cure rate 92%; 95% CI: 78-99%). Both treatment failures reported full compliance to 14 days of therapy. Side-effects were common and resulted in premature discontinuation of therapy in 31%. Premature discontinuation did not reduce the cure rate. CONCLUSION: Quadruple metronidazole combination therapy is effective despite the presence of metronidazole resistance and should be considered as either first line therapy or for failures of twice-a-day combination therapies.

Aged↗

Sustained increase in gastric antral epithelial cell proliferation despite cure of Helicobacter pylori infection.

OBJECTIVE: Studies of the effect of Helicobacter pylori treatment on gastric mucosa proliferation have yielded inconsistent results. We compared gastric mucosa cell proliferation posttherapy and in uninfected controls. METHODS: Biopsies were obtained from patients with H. pylori infection before treatment and at intervals for up to 33 months. Epithelial cell proliferation was determined using Ki-67 immunostaining. The labeling index (LI) is the proportion of positively labeled cells with respect to the total number of cells. The proliferative index was calculated by multiplying the labeling index (LI) and the proliferation zone PZ (PZ = length of the area between the uppermost and lowest labeled cells). RESULTS: The study included 27 patients with H. pylori gastritis and 35 controls. Epithelial cell proliferation (LI) was greater with H. pylori infection than without in both the antrum and corpus (65+/-5 vs 91+/-8 in the antrum and 44+/-4 vs 72+/-8 in the corpus, for uninfected controls vs H. pylori gastritis, respectively) (p = 0.0001). In the antrum there was no significant decrease in epithelial cell proliferation after cure of the H. pylori infection despite follow-up for >2 yr (labeling index = 83+/-10). In contrast, epithelial cell proliferation decreased in the corpus and became similar to that in controls after 7-13 months. CONCLUSIONS: Patients with H. pylori infection have sustained high epithelial cell proliferation in the antrum compared to that in uninfected subjects. A continued increase in proliferation in the antrum after cure of H. pylori infection suggests continuing damage.

Anti-Ulcer Agents↗

Evaluation of gastric mucosal biopsy site and number for identification of Helicobacter pylori or intestinal metaplasia: role of the Sydney System.

Pathologists are frequently asked to evaluate gastric mucosal biopsy specimens for the presence of Helicobacter pylori infection and for potentially important changes such as intestinal metaplasia. No agreed-on system is both available and prospectively shown to provide reliable estimates of the underlying pathological condition. The Sydney System combined topographical, morphological, and causative information for evaluation of gastric biopsy specimens and provided recommendations regarding biopsy site and number. Both the biopsy sites and number were changed in 1994. Gastric biopsy specimens from patients who had multiple biopsies performed on predetermined sites were examined to compare the original and the revised Sydney Systems for the detection of intestinal metaplasia and H pylori. The diagnosis based on both versions of the Sydney System was then compared with that obtained by evaluating all specimens. Forty-six patients were studied, 20 with H pylori infection and 36 with intestinal metaplasia. Using either version of the Sydney System correctly categorized H pylori infection status in 100%. Both the original and the revised Sydney recommendations seriously underestimated the prevalence of intestinal metaplasia. Intestinal metaplasia was missed in more than 50% of those with confirmed intestinal metaplasia. No set or site of biopsy specimens was found that could reliably exclude the presence of intestinal metaplasia. Current and future studies that use the Sydney System as basis for detecting intestinal metaplasia are not likely to be reliable. Likewise, using the Sydney System to test posttherapy or with time will not accurately reflect the true status of intestinal metaplasia.

Adult↗

Ranitidine bismuth citrate, tetracycline, clarithromycin twice-a-day triple therapy for clarithromycin susceptible Helicobacter pylori infection.

BACKGROUND: Although many combination therapies have been proposed, there is still interest in identifying simple, inexpensive, effective protocols that have high rates of success. AIM: To investigate the role of the new soluble form of bismuth, ranitidine bismuth citrate, in twice-a-day therapy for Helicobacter pylori infection. METHODS: Patients with histologically and culture proven H. pylori infection received ranitidine bismuth citrate 400 mg, tetracycline HCl 500 mg, and clarithromycin 500 mg, each b.d. for 14 days, followed by 300 mg ranitidine once a day for 4 additional weeks. Outcome was assessed 4 or more weeks after the end of antimicrobial therapy by repeat endoscopy with histology and culture (49 patients) or urea breath testing (14 patients). RESULTS: Sixty-three patients completed the therapy, 59 men and four women (average age 56.7 years; range 31-75 years). All patients had clarithromycin-susceptible strains prior to therapy. H. pylori infection was cured in 94% (95% CI: 85-98%). There was a therapy failure in one patient who took the medicine for only 1 day and stopped because of side-effects. Three of the isolates from treatment failures were available post-failure; two were clarithromycin-resistant and one was susceptible. Side-effects were severe in two patients (3%) and moderate in three (primarily diarrhoea). CONCLUSIONS: Twice-a-day ranitidine bismuth citrate, tetracycline, clarithromycin triple therapy was well tolerated and effective for the treatment of H. pylori infection in patients with clarithromycin-susceptible H. pylori.

Adult↗

Relationship between the cagA 3' repeat region of Helicobacter pylori, gastric histology, and susceptibility to low pH.

BACKGROUND & AIMS: The variation in size of Helicobacter pylori CagA is related to repeat sequences in the 3' region of the cagA gene. We investigated whether structural subtypes of the cagA 3' region are associated with presentation of the infection or to susceptibility to acid. METHODS: We examined 319 cagA-positive H. pylori isolates: 84 isolates from Bogota, Colombia; 83 from Houston, Texas; 24 from Siena, Italy; and 128 from Seoul, Korea. The cagA 3' region was amplified by polymerase chain reaction. Gastric histology and susceptibility to pH 3 were evaluated in relation to the number of cagA repeat regions. RESULTS: Strains with more than three repeat regions were associated with significantly higher scores for gastric mucosal atrophy and intestinal metaplasia than those with fewer repeat regions. H. pylori strains with three repeat regions were also significantly more susceptible to pH 3 than isolates with fewer repeat regions. CONCLUSIONS: H. pylori strains with more than three repeat regions in the 3' region of the cagA gene are associated with enhanced histological injury and with reduced survival in acidic conditions. It is hypothesized that these variants arise within the stomach.

Adult↗

The differential diagnosis of early gastric mucosa-associated lymphoma: polymerase chain reaction and paraffin section immunophenotyping.

The distinction between benign florid lymphoid hyperplasia and low-grade gastric mucosal-associated lymphoid tissue (MALT) lymphoma may be a challenge. The presence of monoclonal B cells in Helicobacter pylori-chronic active gastritis has suggested that polymerase chain reaction (PCR) data should be viewed with caution. We investigated the reliability of PCR versus immunophenotyping in diagnosing early gastric MALT lymphoma. We studied 1511 biopsies from eight patients with high-grade primary gastric lymphoma, 25 with low-grade MALT lymphoma, 32 with atypical lymphoid infiltrates, and 39 with Helicobacter pylori-chronic active gastritis. Paraffin sections from all cases were stained with antibodies to CD20, CD3, AE1/AE3, kappa and lambda. PCR was performed on paraffin sections using the primer set VH-FR3/J(H). Using histopathology as the gold standard in diagnosis, we confirmed monoclonality in 22 of 25 MALT lymphomas (88%); a clonal band was found in 38% (15 of 39) of patients with chronic active gastritis. An immunophenotype pattern with predominance of CD20-positive cells in lymphocytic infiltrates was associated with monoclonality in 92% of cases. The presence of an enlarged irregular mantle zone was found in both monoclonal and polyclonal areas. An equal prevalence of B and T cells in lymphocytic infiltrates was associated with a polyclonal pattern in 24 of 31 cases (77%). Immunostaining of sIg (kappa and lambda) was difficult in paraffin sections and convincing proof of monoclonality was not obtained. Lymphoepithelial lesions were infrequent in gastric biopsies and their presence was highlighted with keratin stains. Because monoclonal B cells are observed in Helicobacter pylori-associated gastritis, the correct interpretation of clonality by PCR remains unclear. Paraffin section IHC using CD20 and CD3 is especially useful to confirm the diagnosis of gastric MALT lymphoma.

Adult↗

One-week triple therapy with lansoprazole, clarithromycin, and metronidazole to cure Helicobacter pylori infection in peptic ulcer disease in Korea.

The efficacy and acceptability of classical bismuth triple therapy may be limited by poor patient compliance and adverse effects. It is widely agreed that improved, simpler, and reliable therapies are needed to cure Helicobacter pylori infection and foster patient compliance. We evaluated the efficacy and side effects of a Bazzoli triple therapy substituting lansoprazole for omeprazole for H. pylori infection in active peptic ulcer in Korea (30 mg of lansoprazole, 250 mg of clarithromycin, and 400 mg of metronidazole, all twice daily). H. pylori status was evaluated by rapid urease test, histology, and culture at entry and four or more weeks after ending antimicrobial therapy. Fifty-eight patients (mean age: 43 years) with gastric (N = 30) or duodenal ulcer (N = 28) and H. pylori infection were studied. H. pylori was cured in 47 (81%, 95% CI = 69-90%). Mild side effects, including vomiting, diarrhea, and itching, were observed in four patients (7%). Compliance averaged 95%. Fifty-five ulcers (95%) were healed. Pretreatment pylorobulbar deformity was observed in 49 patients (85%), and in 43 (88%) the deformity disappeared after treatment. Pretreatment metronidazole and clarithromycin resistance was observed in 87% and 2% of patients, respectively. The cure rate of H. pylori infection was significantly higher in patients >50 years of age than those <50. Treatment with low-dose one-week lansoprazole, clarithromycin, and metronidazole resulted in a relatively low cure rate, but was well tolerated. Studies to define the optimal duration, dose, and dosing interval of this combination therapy in Korea are needed.

2-Pyridinylmethylsulfinylbenzimidazoles↗

The ChemTrak Hp Chek fingerstick whole blood serology test for the detection of Helicobacter pylori infection.

OBJECTIVE: To evaluate a new whole blood serology test (Hp Chek; ChemTrak) that detects IgG antibodies to Helicobacter pylori. METHODS: The study was conducted at 10 sites within the United States. Patients undergoing upper endoscopy for dyspepsia were recruited for enrollment. Those treated for H. pylori infection within a year of endoscopy and those who had regularly used proton pump inhibitors, bismuth compounds, or antibiotics within a month of endoscopy were not eligible. During endoscopy, specimens were obtained from the corpus and antrum for histological examination, which was performed by a single experienced pathologist. The Hp Chek was tested using whole blood and serum. Serum was also tested with a reference enzyme-linked immunosorbent assay (ELISA) at a centralized location. Test characteristics for the Hp Chek and ELISA were calculated using histology as the "gold standard." RESULTS: Two hundred eighty-seven patients (140 women and 147 men; mean age 53 +/- 6 yr) were enrolled. The Hp Chek was easy to perform and yielded results 9 min after inoculation of the test cassette with whole blood or serum. When the Hp Chek used with whole blood was compared with histology as the gold standard, the sensitivity was 88%, specificity 85%, positive predictive value 83%, negative predictive value 90%, and percent agreement 86%. There were no statistically significant differences among the results obtained with the Hp Chek using whole blood, the Hp Chek using serum, or reference ELISA. CONCLUSIONS: The Hp Chek whole blood serology test was easy to perform and rapid and yielded performance characteristics comparable to those of a reference ELISA or the Hp Chek used with serum.

Analysis of Variance↗