Rhein affects arylamine N-acetyltransferase activity in Helicobacter pylori from peptic ulcer patients

Arylamine N-acetyltransferase (NAT) activities with 2-aminofluorene and p-aminobenzoic acid were determined in the bacterium Helicobacter pylori collected from peptic ulcer patients. Cytosols or suspensions of H. pylori with or without specific concentrations of rhein co-treatment showed different percentages of 2-aminofluorene and p-aminobenzoic acid acetylation. The data indicate that there was decreased NAT activity associated with increased levels of rhein in H. pylori cytosols. Inhibition of growth studies from H. pylori demonstrated that rhein elicited dose-dependent bacteriostatic activity in H. pylori cultures: i.e. the greater the concentration of rhein, the greater the inhibition of growth to H. pylori. For the cytosol and intact bacteria examination, the apparent values of Km and Vmax were decreased after co-treatment with 40 microM rhein. This report is the first demonstration of rhein inhibition of arylamine N-acetyltransferase activity and rhein inhibition of growth in the bacterium H. pylori.

Aloe-emodin effects on arylamine N-acetyltransferase activity in the bacterium Helicobacter pylori

Arylamine N-acetyltransferase (NAT) activities with p-aminobenzoic acid (PABA) and 2-aminofluorene (AF) were determined in H. pylori collected from peptic ulcer patients. Cytosols or suspensions of H. pylori with or without different concentrations of aloe-emodin co-treatment showed different percentages of AF and PABA acetylation. The data indicate that there was decreased NAT activity associated with increased aloe-emodin in H. pylori cytosols. Inhibition of growth study from H. pylori demonstrated that aloe-emodin elicited dose-dependent growth inhibition in H. pylori cultures. The report is the first finding of aloe-emodin inhibition of arylamine NAT activity in a strain of H. pylori.

Fine needle aspiration of the breast. A probabilistic approach to diagnosis of carcinoma

OBJECTIVE

To develop a classification scheme for reporting the results of fine needle aspiration (FNA) cytology of a breast lesion according to its likelihood of being a carcinoma.

STUDY DESIGN

To verify the validity of this scheme, we studied a total of 267 FNAs that were prospectively classified according to predefined criteria as positive (76), suspicious (41), proliferative with atypia (66), proliferative without atypia (48) and unremarkable (36), and compared these results with the final histology.

RESULTS

The percentages of patients who had carcinoma on histology were 100% (76), 93% (38), 35% (23), 6% (3) and 31% (11) of cases diagnosed as positive, suspicious, atypical proliferative, proliferative without atypia and unremarkable on cytology, respectively. However, if only invasive carcinoma is considered, then the percentage of carcinoma was 99% (75), 93% (38), 23% (15), 2% (1) and 11% (4), respectively. The only invasive carcinoma in the proliferative-without-atypia category was a tubular carcinoma and represented a false negative diagnosis. All four invasive carcinomas with an unremarkable cytologic diagnosis were due to sampling errors. Definitive surgery after FNA was common in cases with positive (65%) and suspicious (42%) cytologic diagnosis, whereas all but one patient with atypical, proliferative and unremarkable diagnoses had a biopsy initially.

CONCLUSION

This scheme of reporting breast FNA results with defined criteria according to the probability of identifying carcinoma provides a rational basis for guidelines for the management of breast lesions.

Interobserver variability in the classification of proliferative breast lesions by fine-needle aspiration: results of the Papanicolaou Society of Cytopathology Study

This study evaluates the applicability of the published cytologic criteria in the categorization of proliferative breast lesions by assessing the diagnostic accuracy and interobserver reproducibility of a panel of experts. Twelve breast fine-needle aspiration (FNA) specimens of biopsy-proven nonproliferative breast lesion (NPL) (1 case), proliferative lesions without atypia (PL) (7 cases), proliferative lesion with atypia (PLA) (1 case), and low-nuclear grade ductal carcinoma in situ (DCIS) (3 cases) were selected. Six FNAs were Papanicolaou (PAP) and 6 were Diff-Quik-stained (DQ). Six expert cytopathologists classified the smears using a summary of published criteria as a guideline. All 6 participants rendered the same cytologic diagnosis in 2/12 (16%) cases. The agreement among the 6 raters was low (Kappa = 0.35). Cytohistologic correlation was achieved in 26/72 (36%) FNA diagnoses. The correlation of the PAP-stained cases was better than the DQ: 17/36 (47%) PAP and 9/36 (25%) DQ correlated. Improving the correlation was achieved by amalgamation of NPL and PL into "low risk" and PLA and DCIS into "high risk" categories: 47/72 (65%) FNA diagnoses then correlated with histology [29/36 (81%) PAP and 18/36 (50%) DQ]. We conclude that the cytologic criteria of proliferative breast lesions need to be further defined and assessed. Consideration should be given to minimizing the number of diagnostic categories and adopting a terminology that has a direct effect on patient management.

Secondary structure analysis of individual transmembrane segments of the nicotinic acetylcholine receptor by circular dichroism and Fourier transform infrared spectroscopy

Circular dichroism (CD) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy are used to establish the secondary structure of peptides containing one or more transmembrane segments (M1-M4) of the Torpedo californica nicotinic acetylcholine receptor (AChR). Peptides containing the M2-M3 and M1-M2-M3 transmembrane segments of the AChR beta-subunit and the M4 segment of the alpha- and gamma-subunits were isolated from proteolytic digests of receptor subunits, purified, and reconstituted into lipid vesicles. For each peptide, an amide I vibrational frequency centered between 1650 and 1656 cm-1 and negative CD absorption bands at 208 and 222 nm indicate that the peptide is largely alpha-helical. In addition, the CD spectrum of a tryptic peptide of the alpha-subunit containing the M1 segment is also consistent with a largely alpha-helical structure. However, secondary structure analysis of the alpha-M1 CD spectrum indicates the presence of other structures, suggesting that the M1 segment may represent either a distorted alpha-helix, likely the consequence of several proline residues, or may not be entirely alpha-helical. Overall, these findings are consistent with studies that indicate that the transmembrane region of the AChR comprises predominantly, if not exclusively, membrane-spanning alpha-helices.

Fine-needle aspiration is limited in the classification of benign breast diseases

Fine needle aspiration (FNA) has been proven to be accurate for the detection of breast carcinomas. However, its utility in the classification of benign breast lesions is less clear. We therefore undertook a study of 76 adequate preoperative FNAs of the breast from patients whose surgical biopsies of the breast were shown to be benign (18 nonproliferative diseases, 30 fibroadenomas, 19 proliferative breast diseases without atypia, and 9 proliferative breast diseases with atypia). A number of architectural and cellular features on cytology were evaluated. Histology slides were also reviewed. Both cytology and histology specimens were categorized as nonproliferative disease, fibroadenoma, proliferative breast disease without atypia, and proliferative breast disease with atypia. There was exact diagnostic correlation between cytology and histology in only 42 (55%) of the 76 cases. No cellular or architectural features on FNA examined correlated with the presence of epithelial proliferation on histology. The presence of two epithelial cell populations (one unremarkable and one atypical), small but prominent nucleoli, and nuclear pleomorphism on FNA significantly correlated with the presence of atypia on histology. However, these features are also present in breast lesions without proliferation or atypia, and are not diagnostic of atypical proliferative lesions of the breast. Therefore, FNA of the breast is limited in classifying benign breast diseases.

Activation of phosphoinositide 3-OH kinase by the alpha6beta4 integrin promotes carcinoma invasion

We demonstrate that the alpha6beta4 integrin promotes carcinoma invasion through a preferential and localized targeting of phosphoinositide-3 OH kinase (PI3K) activity. Stable expression of alpha6beta4 increased carcinoma invasion in a PI3K-dependent manner, and transient expression of a constitutively active PI3K increased invasion in the absence of alpha6beta4. Ligation of alpha6beta4 stimulated significantly more PI3K activity than ligation of beta1 integrins, establishing specificity among integrins for PI3K activation. Alpha6beta4-regulated PI3K activity was required for the formation of lamellae, dynamic sites of motility, in carcinoma cells. The small G protein Rac is required downstream of PI3K for invasion. These studies define a mechanism by which the alpha6beta4 integrin promotes carcinoma invasion and invoke a novel function for PI3K signaling.

[Effect of 6-dimethylaminopurine on the resumption of meiosis and parthenogenetic activation in mouse oocytes]

Chromatin condensation and germinal vesicle breakdown (GVBD) in mouse cumulus free oocytes was blocked by 2 mmol/L of 6-DMAP in vitro. Mouse oocytes (M II) from superovulated female mice could be activated by 6-DMAP. The activation rates of oocytes (18-19 h post hCG) cultured in CZB medium with 2 mmol/L 6-DMAP for 0.5, 1, 2, 3 h, were 26.1%, 75.2%, 75.8%, 77.3% respectively (Table 1), and the cleavage rates of these activated oocytes were 88.2%, 73.2%, 67.0%, 58.4% respectively (Table 2). The parthenogenetic activation type induced by 6-DMAP was different from that produced by ethanol (Fig.1).

Hepatocyte primary culture bioassay: a simplified tool to assess the initiation of the liver regeneration cascade

The objective was to develop and optimize a hepatocyte primary culture bioassay to detect proliferative factors (PF) in the serum or plasma of partially hepatectomized (PHX) rats to serve as a tool to assess the initiation of the liver regeneration cascade. The bioassay detects PF by measuring hepatocyte proliferation through directly counting increases in viable cell number over the culture period using a hemocytometer. Hepatocytes were obtained using a two-step collagenase perfusion procedure. The purified hepatocytes (>80% viability, >95% parenchymal cells) were seeded into 6-well culture plates and allowed to attach overnight. The unattached cells were washed out, and the starting cell count was determined from three randomly selected wells after trypsin digestion. Sera from 2/3 PHX rats at 1-6 h postPHX was added to the culture. With a medium change at 24 h, the final cell counting was performed at 48 h. The net cell proliferation was expressed as the difference between the counts at 48 h and starting h. The optimized assay conditions could detect an increase of PF in PHX rat serum between 1 and 4 h after PHX (peaking at 4 h). The bioassay showed both a qualitative and quantitative sensitivity to distinguish between the PF levels in 1/3 and 2/3 PHX rats.

Emodin-induced inhibition of growth and DNA damage in the Helicobacter pylori

Studies were conducted to examine the dose effects of emodin on inhibition of growth versus DNA damage events in H. pylori from patients who had peptic ulcer disease. Inhibition of growth study from H. pylori demonstrated that emodin elicited dose-dependent growth inhibition in H. pylori cultures; that is, the greater the concentration of emodin, the greater the growth inhibition to H. pylori. However, S1 nuclease sensitivity analysis studies revealed that emodin induced dose-dependent DNA damage in H. pylori. Collectively, these results suggest that there was a possible relationship between the dose response to emodin and the inhibition of growth and DNA damage in H. pylori.

Evaluation of CLO test and polymerase chain reaction for biopsy-dependent diagnosis of Helicobacter pylori infection

Helicobacter pylori is now recognized as possibly playing an etiologic role on the development of chronic gastritis, peptic ulcers and adenocarcinoma of the distal stomach. CLO test and polymerase chain reaction (PCR) assay are rapid, biopsy-dependent diagnostic tests for H. pylori identification. In this study, we assessed four diagnostic methods (CLO test, PCR assay, culture and histological examination) for H. pylori detection in biopsy specimens from 78 patients with gastroduodenal diseases and investigating the efficiency of CLO test and PCR assay for the diagnosis of H. pylori infection. H. pylori was identified in 75.6%, 75.6%, 64.1%, 69.2% of patients by CLO test, PCR assay, culture and histological examination, respectively. Compared with the detection of H. pylori by culture and/or histological examination, the sensitivity and specificity of the CLO test were 98.2% and 81.8%, respectively, whereas the sensitivity and specificity of PCR assay were 96.4% and 77.3%, respectively. According to the H. pylori infection state as determined from the results of three concordant tests, the sensitivities of culture, CLO test, histological examination, and PCR assay were 90.9%, 96.4%, 98.2% and 100%, respectively. Whereas, the specificity was 100%, 95%, 95% and 90% for culture, CLO test, histological examination, and PCR assay, respectively. We found that both CLO test and PCR assay were highly sensitive and specific for H. pylori identification; however, PCR assay was more sensitive than other methods for detecting the specimens after patients received treatment. The results of this study suggest that CLO test is a rapid and sensitive method of screening for H. pylori infection and that PCR assay could provide an accurate indication of the state of infection both during treatment for eradication of H. pylori and at follow-up.

Inhibitory actions of emodin on arylamine N-acetyltransferase activity in strains of Helicobacter pylori from peptic ulcer patients

Arylamine N-acetyltransferase (NAT) activities with p-aminobenzoic acid and 2-aminofluorene were determined in Helicobacter pylori, a gram-negative rod bacteria collected from peptic ulcer patients. The NAT activity was determined using a acetyl CoA recycling assay and HPLC. Cytosols or suspensions of H. pylori with and without selected concentrations of emodin co-treatment showed different percentages of 2-aminofluorene and p-aminobenzoic acid acetylation. The data indicate that there were decreased NAT activity associated with increased emodin in H. pylori cytosols. As 400 microns of emodin can obviously inhibit NAT activity both in vitro and in vivo (inhibition rate 90% and 93% for 2-aminofluorene and p-aminobenzoic acid in vitro, and 90% and 92%, respectively, for both substrate in vivo). For in vitro examination, the apparent values of Km and Vmax were 3.12 +/- 0.38 mM and 15.20 +/- 3.16 nmol/min/mg protein for 2-aminofluorene, and 0.56 +/- 0.12 mM and 0.74 +/- 0.09 nmol/min mg protein for p-aminobenzoic acid. However, when emodin was added to the reaction mixtures, the values of apparent Km and Vmax were 2.40 +/- 0.32 mM and 10.62 +/- 0.04 nmol/min/mg protein for 2-aminofluorene, and 0.23 +/- 0.02 mM and 0.62 +/- 0.08 nmol/min/mg protein for p-aminobenzoic acid. For in vivo examination, the apparent Km and Vmax were 0.82 +/- 0.18 mM and 0.92 +/- 0.21 nmol/min/10 x 10(10) colony forming units (CFU) for 2-aminofluorene, and 0.78 +/- 0.14 mM and 0.52 +/- 0.06 nmol/min/ 10 x 10(10) (CFU) for p-aminobenzoic acid. However, when emodin was added to the reaction mixtures, the values of apparent Km and Vmax were 0.50 +/- 0.08 mM and 0.62 +/- 0.22 nmol/min/ 10 x 10(10) (CFU) for 2-aminofluorene, and 0.52 +/- 0.21 mM and 0.26 +/- 0.04 nmol/min/ 10 x 10(10) (CFU) for p-aminobenzoic acid. This report is the first finding of emodin inhibition of arylamine N-acetyltransferase activity in a strain of H. pylori.

Morphology of Barrett's esophagus and Barrett's-associated dysplasia and adenocarcinoma

This article has reviewed the morphologic features of BE and its complications of dysplasia and adenocarcinoma in routinely processed endoscopic biopsy and resection specimens. In addition, the problems related to the diagnosis of dysplasia in tissue samples have been analyzed, and the role of esophageal brush cytology in the diagnosis of these lesions has been reviewed.

Central control mechanisms in hypertension

There is substantial evidence for an activation of the sympathetic nervous system in man as well as in genetic models of hypertension, such as the spontaneously hypertensive rat (SHR), but we are only beginning to understand the central mechanisms that generate changes in sympathetic activity and elevate blood pressure (BP). Significant recent advances have been made in defining the neural pathways involved in BP regulation and in identifying the neurotransmitters these neurones utilise. In this overview, we describe the neural pathways within the medulla oblongata and spinal cord that participate in BP control and examine the role of amino acid neurotransmitters within these pathways. We demonstrate how alterations in these pathways explain the sympathetic activation observed in the SHR and contribute to hypertension in this model. Lastly, we examine the application of modern molecular biological approaches to further our understanding of the neural regulation of the circulation. In these studies, we used the administration of antisense oligonucleotides to interrupt gene expression.

Cytologic features of neoplastic lesions in endocervical glands

Cytologic criteria for classifying atypical endocervical cells on Pap smears are poorly defined. In this study we evaluated cytologic parameters that are useful in predicting the presence of neoplastic lesions (NL) and those that help distinguish squamous intraepithelial lesion (SIL) from glandular neoplastic lesions. The recently proposed Bethesda System (TBS) terminology for reporting atypical glandular cells of undetermined significance (AGUS) was also evaluated for its significance on patient management. Sixteen cases of biopsy-proven endocervical glandular NL that had cytologic smears available for review were included. Thirty-five smears with atypical endocervical cells and follow-up biopsies showing benign/reactive change (n = 22) and SIL involving glands (n = 13) were reviewed for comparison. Our results show that squamous NL often coexist with glandular NL. The presence of rosettes, hyperchromasia and increased N/C ratio is useful in distinguishing NL from benign/reactive conditions. Architectural features are helpful in distinguishing SIL from glandular NL. While a haphazard arrangement is more often seen with SIL, glandular NL are more likely to maintain polarity and to show glandular rosettes. Using TBS criteria, a conservative management seems justified in patients with AGUS-favor reactive and AGUS diagnosis on Pap smear, and colposcopy is indicated for patients with AGUS-favor NL.

Value of cytology in detecting intestinal metaplasia and associated dysplasia at the gastroesophageal junction

Tissue sampling is essential for detecting intestinal metaplasia in the distal esophagus (Barrett's esophagus), because symptoms and endoscopy are not reliable in making this diagnosis. The utility of cytology in this process is unknown. All adult patients having elective upper gastrointestinal endoscopy over a 6-month period were invited to participate in a prospective study whose aim was to determine the prevalence of intestinal metaplasia in the distal esophagus in an adult population with diverse upper gastrointestinal symptoms. Clinical data and endoscopic findings were recorded. Brush cytology and biopsy specimens were obtained from both sides of the apparent squamocolumnar junction. The cytology specimens were processed routinely, stained with the Papanicolaou technique, and reviewed blinded to the clinical information and the histological findings in the corresponding biopsy specimens. One hundred fifty-five patients (81 women, 74 men; 137 whites, 11 blacks, 7 others; mean age, 52 years) were included. Glandular epithelium/cells were present on both histology and cytology in 147 specimens. Thirty-two patients (22%) showed intestinal metaplasia on histology. Of the cytology specimens from these 32 patients, 6 contained definite goblet cells (19%), 7 probable goblet cells, and 19 no goblet cells. Goblet cells and probable goblet cells were observed on cytology in 7 and 11 additional specimens, respectively. One was from a patient known to have intestinal metaplasia in the esophagus. Follow-up endoscopy with biopsy was performed in two of these latter 18 patients and did not show intestinal metaplasia. One case of high-grade dysplasia, two of low-grade dysplasia, and three indefinite for dysplasia were diagnosed on histology. All three cases of dysplasia were also identified on cytology. The three indefinite cases on histology were considered reactive in two and unremarkable in one on cytology. Low-grade dysplasia was diagnosed on cytology alone on two cases. Follow-up endoscopy with biopsy was performed in one patient, and low-grade dysplasia was found. Cytology using the Papanicolaou stain is not as sensitive and specific as histology for detecting intestinal metaplasia in the distal esophagus. However, it may be at least as useful as tissue sampling in detecting dysplasia.

Evidence for arylamine N-acetyltransferase activity in the bacterium Helicobacter pylori

N-Acetyltransferase activities with p-aminobenzoic acid and 2-aminofluorene were determined in Helicobacter pylori from gastroduodenal disease patients. The N-acetyltransferase activity was determined using an acetyl CoA recycling assay and high pressure liquid chromatography. The N-acetyltransferase activities from a number of Helicobacter pylori samples were found to be 0.91 +/- 0.12 nmole/min/mg protein for the acetylation of 2-aminofluorene and 0.75 +/- 0.22 nmole/min/mg protein for the acetylation of p-aminobenzoic acid. The apparent K(m) and V(max) values obtained were 1.10 +/- 0.08 mM and 2.34 +/- 0.14 nmol/min/mg protein for 2-aminofluorene, and 0.92 +/- 0.09 mM and 2.08 +/- 0.16 nmol/min/mg protein for p-aminobenzoic acid. The optimal pH value for the enzyme activity was 6.0 for both substrates tested. The optimal temperature for enzyme activity was 37 degrees C for both substrates. The N-acetyltransferase activity was inhibited by iodacetamide: at 0.25 mM iodacetamide, activity was reduced 50% and 1.0 mM iodacetamide inhibited activity more than 90%. Among a series of divalent cations and salts, Cu2+ and Zn2+ were demonstrated to be the most potent inhibitors. Among the protease inhibitors, only ethylenediaminetetraacetic acid significantly protected N-acetyltransferase. Iodoacetic acid, in contrast to the other agents, markedly inhibited N-acetyltransferase. This is the first demonstration of acetyl CoA:arylamine N-acetyltransferase activity in Helicobacter pylori.

[Identification of Candida albicans by specific primers of polymerase chain reaction and DNA probes]

Candida albicans is a pathogenic yeast. Two sets of universal primers were used for specific identification of Candida albicans with PCR-amplified ribosomal DNA internal transcribed spacers (ITS). Among the species of Candida, the amplified ITSI and ITSII of DNA fragments were similar in size. The PCR product was purified and labeled with digoxigenin and used as DNA probe in the detection with target DNA of Candida albicans by hybridization. Two sets of specific primers (CA1 and CA2 to amplify ITSI, CA3 and CA4 to amplify ITSII) were designed by alignment of ribosomal ITS sequence of pathogenic Candida albicans with other species to detect C. albicans by PCR. The sensitivity of PCR using the specific primers to detect pure culture of C. albicans was 0.1 ng (about 10(3)-10(4) cells). If the yeast cells were mixed with two other strains, there was a 10-fold decrease in sensitivity (1 ng or 10(4)-10(5) cells) under the same PCR conditions.

A clinical study on physiological response in electroacupuncture analgesia and meperidine analgesia for colonoscopy

Fifty-nine patients underwent consecutive colonoscopic examination with premedication of electroacupuncture analgesia (EA) were compared with conventional meperidine analgesia (MA) in pain relief and changes of neurotransmitters in serum. The results showed that analgesic efficacy of both groups were the same but with less side effects in the EA group (P < 0.01) especially in regard to dizziness. Serum concentration of beta-endorphin in both groups has a similar curve change at 4 different phases during colonoscopy. Serum concentration of epinephrine, norepinephrine, dopamine and cortisol showed no significant difference between these two groups. The analgesic effect of EA and MA during colonoscopic examination may be closely related to beta-endorphin production in serum.

A study of the relationship between IgG subclass/IgM and idiopathic nephrotic syndrome

In an attempt to elucidate the relationship between serum IgG subclass/IgM ratio and prognosis in different types of idiopathic nephrotic syndrome (INS), 46 cases of treatment responders and 23 cases of either frequent relapse or non-responders were studied. All patients had received renal biopsy. Serum IgG subclass/IgM ratios were compared between the acute nephrotic phase and remission. The association between therapeutic effect and the parameters of INS were also investigated. There were 24 cases of minimal change nephrotic syndrome (MCNS), 32 cases of IgM nephropathy (IgMN) and 13 cases of focal segmental glomerular sclerosis (FSGS). All cases of MCNS were steroid-responders. Seventeen cases of IgMN experienced frequent relapses. The other 15 cases were responsive to the treatment. 6 cases of FSGS had poor response to any therapy; 7 cases were responsive to either triple therapy or cyclosporine A plus prednisolone. Both IgGI/IgM and IgG2/IgM were correlated with serum albumin and cholesterol levels at the acute nephrotic phase (p < 0.05). Longitudinal change of the immunologic parameters in patients with INS revealed significantly elevated serum IgM level decreased serum IgG level, IgG/IgM, IgG1/IgM, IgG2/IgM, IgG3/IgM, IgG4/IgM and IgG/IgE ratio during acute nephrotic phase. Correlation between therapy responses showed that, for serum IgG1/IgM ratio > 3.0, most of the cases were treatment-responders. For IgG1/IgM ratio > 1.0, all the cases were frequent relapsers or non-responders. These results suggest the immunologic changes in patients of INS may be caused by immune regulatory abnormality. Serum IgG1/IgM ratio may serve as one of the therapeutic and prognostic guides, especially if the patient refuses renal biopsy.

Prevalence and significance of pancreatic acinar metaplasia at the gastroesophageal junction

Pancreatic acinar metaplasia (PAM), defined as nodules of glandular tissue forming acini composed of cells with coarse apical eosinophilic granules, with or without mucous cells, was recently recognized in gastric mucosa, but its significance is not known. As part of a study on intestinal metaplasia at the gastroesophageal junction (GEJ), we evaluated the prevalence and clinical and histologic correlates of PAM in biopsy specimens from the gastroesophageal squamocolumnar junction. All adult patients having elective upper gastrointestinal endoscopy over a 6-month period were invited to participate. Clinical data and endoscopic findings were recorded. Biopsy specimens, obtained from both sides of the apparent squamocolumnar junction, were processed routinely and reviewed (without knowledge of the clinical data) to evaluate types of epithelium, types and degree of inflammation, and the presence of PAM. The presence or absence of PAM was then correlated with the other histologic findings and with the clinical and endoscopic data. The study comprised 155 patients (79 women, 76 men; 139 white patients, nine black patients, and seven patients of other ethnic groups). Their mean age was 52 years (range: 18-89 years). PAM was present in 37 patients (24%). PAM was not associated with any of the reported symptoms, endoscopic evidence of esophagitis or columnar epithelium in the distal esophagus, or any of the histologic features evaluated, including active esophagitis, intestinal metaplasia at the GEJ, active and chronic gastritis, intestinal metaplasia in the stomach, and Helicobacter infection. Although PAM is present in a considerable proportion (24%) of patients with mucosal biopsy specimens from the squamocolumnar junction, it appears to be an incidental finding unrelated to clinical or histologic abnormalities. We therefore suggest a congenital, rather than an acquired, origin for this entity.

Effective reduction of Helicobacter pylori infection after upper gastrointestinal endoscopy by mechanical washing of the endoscope

BACKGROUND/AIMS

To investigate the frequency of endoscopic transmission of Helicobacter pylori and the efficiency of disinfection in different washing methods of endoscopes.

MATERIALS AND METHODS

IgG antibodies to H. pylori in patients prospectively followed who underwent first endoscopic examination at the National Taiwan University Hospital from 1982 to 1993 were measured. A total of 132 subjects who were negative for H. pylori IgG antibody test before examination and who were with negative endoscopic findings were enrolled. Among the 132 seronegative patients, 60 were examined before June 1989 when manual washing was adopted for endoscope cleaning and 72 received examination after mechanical washing were routinely used in our endoscopy unit.

RESULTS

During a follow-up period of 6 months or more, 5 patients in the manual washing group sero-converted while none in the mechanical washing group seroconverted (5/60 vs 0/72. p = 0.02).

CONCLUSION

The results suggested that the risk of endoscopic transmission of H. pylori is substantial and mechanical washing is efficient in preventing this iatrogenic spread.

Low-grade gastric B-cell lymphoma of mucosa-associated lymphoid tissue: clinicopathologic analysis of 19 cases

Low-grade gastric B-cell lymphoma of mucosa-associated lymphoid tissue type (MALToma) is a recently recognized disease entity. We report the clinicopathologic features of 19 patients with MALToma in Taiwan. The 19 patients included eight men and 11 women, ranging in age from 26 to 77 years, with a mean age of 58.8 years. Most complained of abdominal pain or gastrointestinal bleeding. The endoscopic and gross features of the gastric lesions revealed erosion (flat type), ulceration (depressed type), cobblestone appearance or abnormal gastric folds (elevated type), mimicking chronic gastritis, ulcer or early gastric carcinoma. Typical histopathologic features included lymphoepithelial lesion and extensive mucosal infiltration of centrocyte-like cells in all cases. Clonality analysis of the variable-diversity-joining region of the immunoglobulin gene by semi-nested polymerase chain reaction demonstrated monoclonality in 72% of the cases. Helicobacter pylori bacilli (H. pylori) could be identified on histologic sections in 15 cases (78.9%); the serologic test for H. pylori was positive in 12 of 13 patients tested (92%). In six patients receiving triple therapy (amoxicillin, bismuth subcitrate and metronidazole), five showed significant histologic regression with eradication of H. pylori 4 to 6 months after the start of treatment; one patient showed persistent lesions and presence of H. pylori. However, persistence of residual lymphoid cells and monoclonality of the immunoglobulin gene, could still be demonstrated in four cases. Of nine patients treated with surgery or chemotherapy, two died: one due to concomitant gastric carcinoma and the other one due to sudden apnea. No recurrence was observed in the remaining seven patients. The remaining four patients were lost to follow-up. Our experience confirmed that gastric MALToma is a low-grade neoplastic process. The dramatic response of gastric MALToma to anti-H. pylori treatment suggests that H. pylori infection is closely related to the pathogenesis of low-grade gastric MALToma. However, long-term follow-up is mandatory due to the persistence of the monoclonality of the immunoglobulin gene in the residual lymphoid cells after treatment.