[Prediction of Helicobacter pylori Infection by Endoscopic Severity of Erythematous/exudative Gastritis in Asymptomatic Adults]

BACKGROUND/AIMS

Helicobacter pylori (H. pylori) infection highly correlates with erythematous/exudative gastritis, which is one of the endoscopic findings of the Sydney classification system. The present study aimed to evaluate the association between endoscopic severity of erythematous/exudative gastritis and H. pylori infection.

METHODS

We prospectively enrolled asymptomatic adults who were diagnosed with erythematous/exudative gastritis during screening esophagogastroduodenoscopy. A rapid urease test was performed in all participants to diagnose H. pylori infection. The severity of erythematous/exudative gastritis was determined based on the Sydney classification system. Two investigators independently evaluated the endoscopic findings. The primary endpoint was H. pylori infection rate according to the severity of erythematous/exudative gastritis (mild vs. moderate-to-severe).

RESULTS

A total of 177 patients with erythematous/exudative gastritis were included. The rate of H. pylori infection was 86.4% in all patients. Of 177 included patients, 78 were at mild degree, 48 were at moderate degree, and 51 were at severe degree. The inter-observer variation was 4.6% and kappa value was 0.593. H. pylori infection rate was similar between patients with mild erythematous/exudative gastritis and those with moderate-to-severe erythematous/exudative gastritis (91.0% vs. 82.8%, p=0.115). Even after adjusting potential confounding variables, the severity of erythematous/exudative gastritis was not associated with H. pylori infection rate.

CONCLUSIONS

H. pylori infection is commonly observed in patients with erythematous/exudative gastritis. However, the severity of erythematous/exudative gastritis is not associated with H. pylori infection rate.

Clinical Features and Long-Term Outcomes of Paediatric-Onset Inflammatory Bowel Disease in a Population-Based Cohort in the Songpa-Kangdong District of Seoul, Korea

BACKGROUND AND AIMS

The long-term outcomes of paediatric-onset inflammatory bowel disease [pIBD] in non-Caucasian populations are unknown. We therefore evaluated and compared the clinical features and long-term outcomes of pIBD with those of adult-onset IBD [aIBD] using a population-based cohort in the Songpa-Kangdong district of Seoul, Korea.

METHODS

Clinical characteristics and prognoses were compared between the two groups: pIBD [defined as <18 years of age at diagnosis] and aIBD [18-59 years of age at diagnosis].

RESULTS

We identified 131 patients with pIBD (48 ulcerative colitis [UC], 83 Crohn's disease [CD]) and 1192 patients with aIBD [866 UC, 326 CD] during 1986-2015. Extensive colitis at diagnosis was more prevalent in pUC than in aUC [45.8% vs 22.3%, p < 0.001], and the overall exposure to corticosteroids, thiopurines and anti-tumour necrosis factor agents was higher in pUC than in aUC [p < 0.001]. The cumulative risk of colectomy was higher in pUC than in aUC during a median follow-up of 125.0 and 112.1 months, respectively [8.9% vs 1.8% at 10 years after diagnosis, p = 0.030]. Ileocolonic location and inflammatory behaviour at diagnosis were more common in pCD than in aCD; however, patients with pCD and aCD did not differ regarding treatment or disease course during a median follow-up of 137.2 and 120.9 months, respectively.

CONCLUSION

Our study showed clear differences between pIBD and aIBD, especially in UC. pUC presents with more extensive diseases and may have a more severe disease course, as suggested by an earlier time to administering medications and performing colectomy.

Changes in the Long-term Prognosis of Crohn's Disease between 1986 and 2015: The Population-Based Songpa-Kangdong Inflammatory Bowel Disease Cohort Study

Background/Aims

The long-term course of Crohn’s disease (CD) has never been evaluated in non-Caucasian population-based cohorts. The aim of the present study was to evaluate the long-term prognosis of Korean CD patients in the well-defined population-based Songpa-Kangdong inflammatory bowel disease cohort.

Methods

Outcomes of disease and their predictors were evaluated for 418 patients diagnosed with CD between 1986 and 2015.

Results

During a median of 123 months, systemic corticosteroids, thiopurines, and anti-tumor necrosis factor (TNF) agents were administered to 58.6%, 81.3%, and 37.1% of patients, respectively. Over time, the cumulative probability of starting corticosteroids significantly decreased (p=0.001), whereas that of starting thiopurines and anti-TNFs significantly increased (both p<0.001). The cumulative probability of behavioral progression was 54.5% at 20 years, and it significantly decreased during the anti-TNF era. Intestinal resection was required for 113 patients (27.0%). The cumulative probabilities of intestinal resection at 1, 5, 10, 20, and 25 years after CD diagnosis were 12.7%, 16.5%, 23.8%, 45.1%, and 51.2%, respectively. Multivariable Cox regression analysis identified stricturing behavior at diagnosis (adjusted hazard ratio [aHR], 2.70; 95% confidence interval [CI], 1.55 to 4.71), penetrating behavior at diagnosis (aHR, 11.15; 95% CI, 6.91 to 17.97), and diagnosis of CD during the anti-TNF era (aHR, 0.51; 95% CI, 0.35 to 0.76) as independently associated with intestinal resection. The standardized mortality ratio among CD patients was 1.36 (95% CI, 0.59 to 2.68).

Conclusions

The long-term prognosis of Korean patients with CD is at least as good as that of Western CD patients, as indicated by the low intestinal resection rate. Moreover, behavioral progression and intestinal resection rates have decreased over the past 3 decades.

Clinical Characteristics and Long-term Prognosis of Elderly-Onset Ulcerative Colitis in a Population-Based Cohort in the Songpa- Kangdong District of Seoul, Korea

Background/Aims

We aimed to evaluate the clinical characteristics and long-term prognosis of elderly-onset ulcerative colitis (EOUC) in Korean patients over a 30-year period using a well-established population-based cohort in the Songpa-Kangdong district of Seoul, Korea.

Methods

Clinical characteristics and prognosis were compared between two groups EOUC, defined as UC diagnosed in individuals aged ≥60 years and non-EOUC (N-EOUC), defined as UC diagnosed in individuals aged 18 to 59 years.

Results

We identified 99 patients with EOUC (10.3%) and 866 patients with N-EOUC (89.7%) between 1986 and 2015. During the median follow-up of 104.5 months, the overall exposure to medications was comparable between patients with EOUC and N-EOUC (p=0.091 for corticosteroids, p=0.794 for thiopurines, and p=0.095 for anti-tumor necrosis factor agents). The cumulative risks of disease outcomes were also comparable between patients with EOUC and N-EOUC (22.4% vs 30.4% for proximal disease extension [p=0.351], 11.9% vs 18.1% for hospitalization [p=0.240], and 2.3% vs 1.8% for colectomy [p=0.977]) at 10 years after diagnosis. Multivariate Cox regression analysis revealed that corticosteroid use at diagnosis was an independent predictor of proximal disease extension (hazard ratio [HR], 6.216; 95% confidence interval [CI], 1.314 to 28.826) and hospitalization (HR, 11.241; 95% CI, 3.027 to 41.742) in patients with EOUC.

Conclusions

In this population-based study from Korea, the pattern of medication use seemed comparable between the EOUC and N-EOUC groups. Moreover, patients with EOUC and those with N-EOUC have a similar disease course in terms of proximal disease extension, hospitalization, and colectomy. (Gut Liver 2021;15-751)

Long-term prognosis of ulcerative colitis and its temporal changes between 1986 and 2015 in a population-based cohort in the Songpa-Kangdong district of Seoul, Korea

OBJECTIVE

No population-based study has evaluated the natural course of UC over three decades in non-Caucasians. We aimed to assess the long-term natural course of Korean patients with UC in a population-based cohort.

DESIGN

This Korean population-based, Songpa-Kangdong IBD cohort included all patients (n=1013) newly diagnosed with UC during 1986-2015. Disease outcomes and their predictors were evaluated.

RESULTS

During the median follow-up of 105 months, the overall use of systemic corticosteroids, thiopurines and antitumour necrosis factor (anti-TNF) agents was 40.8%, 13.9% and 6.5%, respectively. Over time, the cumulative risk of commencing corticosteroids decreased, whereas that of commencing thiopurines and anti-TNF agents increased. During follow-up, 28.7% of 778 patients with proctitis or left-sided colitis at diagnosis experienced proximal disease extension. A total of 28 patients (2.8%) underwent colectomy, demonstrating cumulative risks of colectomy at 1, 5, 10, 20 and 30 years after diagnosis of 1.0%, 1.9%, 2.2%, 5.1% and 6.4%, respectively. Multivariate Cox regression analysis revealed that extensive colitis at diagnosis (HR 8.249, 95% CI 2.394 to 28.430), ever use of corticosteroids (HR 6.437, 95% CI 1.440 to 28.773) and diagnosis in the anti-TNF era (HR 0.224, 95% CI 0.057 to 0.886) were independent predictors of colectomy. The standardised mortality ratio in patients with UC was 0.725 (95% CI 0.508 to 1.004).

CONCLUSION

Korean patients with UC may have a better clinical course than Western patients, as indicated by a lower colectomy rate. The overall colectomy rate has continued to decrease over the past three decades.

A 30-year Trend Analysis in the Epidemiology of Inflammatory Bowel Disease in the Songpa-Kangdong District of Seoul, Korea in 1986-2015

BACKGROUND AND AIMS

Although the incidence of inflammatory bowel disease [IBD] is increasing in Asia, data on long-term epidemiological trends are limited. We performed a 30-year longitudinal study to investigate temporal trends in the epidemiology of Crohn's disease [CD] and ulcerative colitis [UC] in Seoul, Korea.

METHODS

This population-based study included 1431 IBD patients [418 CD, 1013 UC] diagnosed between 1986 and 2015 in the Songpa-Kangdong district of Seoul, Korea. Temporal trends in incidence, prevalence, and disease phenotype at diagnosis were analysed.

RESULTS

The adjusted mean annual incidence rates of CD and UC per 100 000 inhabitants increased from 0.06 (95% confidence interval [CI], 0.05-0.07) and 0.29 [95% CI, 0.27-0.31], respectively, in 1986-1990 to 2.44 [95% CI, 2.38-2.50] and 5.82 [95% CI, 5.73-5.92], respectively, in 2011-2015. Average annual percentage change in IBD incidence was 12.3% in 1986-1995, 12.3% in 1996-2005, and 3.3% in 2006-2015. The male-to-female ratio of the adjusted incidence rate was 3.3:1 for CD and 1.2:1 for UC. Perianal fistula/abscess was present in 43.3% of patients before or at CD diagnosis. At diagnosis, 54.3% of UC patients presented only with proctitis. The adjusted prevalence rate in 2015 was 31.59/100 000 [95% CI, 31.10-32.07] for CD and 76.66/100 000 [95% CI, 75.91-77.42] for UC.

CONCLUSIONS

The incidence and prevalence of IBD in Korea have continued to increase over the past three decades. Korean patients have distinct demographic and phenotypic characteristics, including a male predominance and high frequency of perianal fistula/abscess in CD and high proportion of proctitis in UC.

Comparison of transnasal small-caliber vs. peroral conventional esophagogastroduodenoscopy for evaluating varices in unsedated cirrhotic patients

BACKGROUND AND STUDY AIMS

We aimed to evaluate the accuracy of transnasal small-caliber esophagogastroduodenoscopy (TNSC-EGD) compared with peroral conventional EGD (POC-EGD) for evaluating varices in unsedated patients with liver cirrhosis. The success rate, safety, endoscopist satisfaction, and patient tolerability of TNSC-EGD were also addressed.

PATIENTS AND METHODS

One hundred patients with liver cirrhosis participated in this randomized crossover trial, and 84 subjects completed both procedures. Of the 84 patients, 28 had marked bleeding diathesis (platelet count ≤ 50000/mm (3) and/or prothrombin time ≥ 1.7 INR). Endoscopists and patients answered questionnaires using a 100-mm visual analog scale about, respectively, their satisfaction and their tolerance of the procedure.

RESULTS

The success rate of TNSC-EGD was comparable to that of POC-EGD (96% vs. 99%). Nasal mucosal hemorrhages induced by TNSC-EGD occurred in 5 patients (6%), but were easily controlled. Compared to the POC-EGD reference test, diagnostic accuracies of TNSC-EGD for detecting esophageal varices, gastric varices, and red color signs were 98%, 98%, and 96%, respectively. Concordance rates on grading esophageal varices and gastric varices were excellent at 93% (κ  =  0.85) and 96% (κ  = 0.87). Endoscopist satisfaction was not significantly different between TNSC-EGD and POC-EGD, whereas patient tolerance of TNSC-EGD was significantly greater than that of POC-EGD (79.0 ± 14.4 vs. 69.5 ± 16.1; P  = 0.001).

CONCLUSION

TNSC-EGD without sedation was found to be feasible, safe, and accurate for evaluating esophageal varices, gastric varices, and red color signs in patients with cirrhosis - even in those with marked bleeding diathesis. Furthermore, it was significantly better tolerated by patients, without altering endoscopist satisfaction. Our findings indicate that TNSC-EGD without sedation might be viewed as a potential alternative to POC-EGD for evaluation of varices.

Does a small biopsied gastric specimen limit the usage of two directional transnasal esophagogastroduodenoscopy?

BACKGROUND AND AIMS

It is difficult to approach certain gastric regions due to the limited bending ability of transnasal esophagogastroduodenoscopy (TN-EGD). We analyzed the TN-EGD biopsied specimens according to where they were obtained inside the stomach.

METHODS

Two hundred and eighty-nine gastric biopsy specimens were obtained during diagnostic TN-EGD. The gastric biopsied specimens were quantified according to their diameter and depth in micrometers, and depth in layers (superficial mucosa, deep mucosa, muscularis mucosa and submucosa). The quality was measured by the degrees of anatomical orientation (good, intermediate and poor), presence of crush artifact (none to minimal, mild and moderate) and overall diagnostic adequacy (adequate, suboptimal and inadequate).

RESULTS

Poor orientation, presence of crush and overall diagnostic inadequacy were present in 33 (11.4%), 26 (9.0%) and 37 (12.8%) of the 289 specimens, respectively. Deep mucosa was present in 211 specimens (73.0%), while muscularis mucosa was present in only 75 specimens (26.0%). Specimens taken from the posterior aspect of the cardia exhibited the shallowest depth (P = 0.011), poorest orientation (P < 0.001) and poorest diagnostic adequacy (P < 0.001). Fluoroscopic findings demonstrated that the posterior aspect of the cardia was difficult to approach closely and perpendicularly because of the anatomical configuration of the stomach in nature.

CONCLUSION

TN-EGD biopsied specimens obtained from the posterior aspect of the cardia exhibit limitations in both quality and quantity. When performing a biopsy using two directional TN-EGD, special attention should be paid to gastric lesions located on the posterior aspect of the cardia.

[Cytomegalovirus infection-related spontaneous intestinal perforation and aorto-enteric fistula after abdominal aortic aneurysmal repair]

Gastrointestinal complications (GI) after thoracoabdominal aortic repair can be classified as biliary disease, heptic dysfunction, pancreatitis, GI bleeding, peptic ulcer disease, bowel ischemia, paralytic ileus, and aortoenteric fistula. Theses complications are associated with high post operative morbidity and mortality. Most of the aortoenteric fistulae after thoracoabdominal aortic surgery are found at the duodenum, near the surgical site. These rare complications are caused by an indirect communication with abdominal aorta that originated from an aneursymal formation ruptured into the duodenum. Such aorto-duodenal fistula formation is considered as a result of inflammatory change from secondary infection near the surgical instruments. Herein, we report two cases of massive upper GI bleeding from aorto-duodenal fistulae and spontaneous lower GI perforation related to cytomegalovirus infection after abdominal aortic aneurysmal repair operations.

Clevudine myopathy in patients with chronic hepatitis B

Clevudine (L-FMAU) is a thymidine l-nucleoside analogue that was recently introduced for the treatment of chronic hepatitis B virus infection. Previous studies showed that clevudine has potent and sustained antiviral activity without causing viral resistance. No severe adverse event occurred during clinical trials. We describe two cases of drug-induced myopathy during long-term treatment of chronic hepatitis B with clevudine.

Endoscopic ultrasonography-guided trucut biopsy for the preoperative diagnosis of peripancreatic castleman’s disease: A case report

Castleman’s disease (CD) of the pancreas/peripancreas is extremely rare. The recently introduced, endoscopic ultrasonography (EUS)-guided trucut biopsy (TCB) is a useful diagnostic modality for obtaining tissue samples from peripancreatic lesions. However, its role in diagnosing CD remains unknown. We report a case of localized, peripancreatic, hyaline-vascular CD biopsied using EUS. The pathology results were initially interpreted as an extranodal, marginal-zone B-cell lymphoma. However, polymerase chain reaction (PCR) study for the IgH gene rearrangement revealed a polyclonal pattern. We also reviewed the relevant literature. To our knowledge, this is the first illustrated report on EUS-TCB findings of CD with its pathology results of EUS-TCB mimicked a B-cell lymphoma.

Mediastinal single nodal relapse of a nasal NK/T cell lymphoma

A nasal NK/T cell lymphoma is a very aggressive form of lymphoma. Patterns of relapse after treatment have not been systematically evaluated, and mediastinal nodal relapse at a primary site has never been documented. We describe here a 40-year old man who presented with a nasal obstruction caused by a protruding mass that was identified as a nasal NK/T cell lymphoma. The initial work-up, including chest and abdominopelvic computed tomography (CT) and positron emission tomography (PET), showed no regional or distant metastasis. A CT scan performed following three cycles of chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) showed that the mass had nearly disappeared. Radiation therapy undertaken following chemotherapy was given to the primary site. However, PET performed following radiotherapy revealed a single mediastinal lymphadenopathy, with no evidence of residual tumor in the nasal cavity. A biopsy using video-assisted thoracoscopy (VATS) showed the presence of a recurrent NK/T cell lymphoma with an immunophenotype identical to that of the primary nasal lymphoma. An additional three cycles of CHOP chemotherapy were administered, and the patient remains alive, with no evidence of disease 30 months after the initial relapse. These findings indicate that early detection with PET and prompt surgical excision with the use of VATS can lead to successful treatment of a relapsed nasal NK/T cell lymphoma.

Photosystem II: the solid structural era

Understanding the precise role of photosystem II as an element of oxygenic photosynthesis requires knowledge of the molecular structure of this membrane protein complex. The past few years have been particularly exciting because the structural era of the plant photosystem II has begun. Although the atomic structure has yet to be determined, the map obtained at 6 A resolution by electron crystallography allows assignment of the key reaction center subunits with their associated pigment molecules. In the following, we first review the structural details that have recently emerged and then discuss the primary and secondary photochemical reaction pathways. Finally, in an attempt to establish the evolutionary link between the oxygenic and the anoxygenic photosynthesis, a framework structure common to all photosynthetic reaction centers has been defined, and the implications have been described.

Invasiveness of Helicobacter pylori into human gastric mucosa

BACKGROUND

Helicobacter pylori has generally been observed only in the gastric mucous layer or in the spaces between gastric mucus-secreting cells and not in the gastric epithelial cells or in the lamina propria. The purpose of this study is to determine whether H. pylori invades the gastric mucosa, using an immunoelectron microscopical examination of human gastric mucosa infected with H. pylori.

MATERIALS AND METHODS

Five hundred gastric antral biopsy specimens were fixed in a periodate-lysin-paraformaldehyde solution, embedded in Lowicryl, sectioned, and examined with a light microscope. One hundred specimens moderately or severely infected with H. pylori were selected and were incubated with polyclonal rabbit anti-H. pylori antibody. The specimens were washed, incubated with 20 nm of colloidal gold-conjugated goat anti-rabbit IgG, stained with uranyl acetate and lead citrate, and observed with a transmission electron microscope.

RESULTS

In one case, a bacterium was observed within the cytoplasm of a gastric mucus-secreting cell; in another case, a few bacteria were observed within the cytoplasm of a stromal cell in the lamina propria. The bacteria could be differentiated from degenerated intracellular organelles by gold particles attached to the bacteria.

CONCLUSION

H. pylori rarely invade the lamina propria and gastric cells.

Purpura fulminans associated with Streptococcus pneumoniae infection in a child

BACKGROUND

Neisseria meningitidis is the most frequent isolate associated with purpura fulminans in children. Although Streptococcus pneumoniae infection has been associated with purpura fulminans, with the exception of one adult, it has only been reported in immunocompromised hosts.

PURPOSE

We report an apparently previously healthy child who presented with purpura fulminans associated with pneumococcal meningitis.

METHODS

Case report and review of the medical literature from September 1966 to June 1997, using a MEDLINE search.

CONCLUSION

While systemic pneumococcal infection is common in childhood, progression to purpura fulminans does not typically occur in overtly healthy children. Our patient illustrates that invasive pneumococcal infection should be considered and empirically treated in a child who presents with purpura fulminans, even in the absence of preexisting functional or anatomic asplenia.

Three-dimensional structure of the plant photosystem II reaction centre at 8 A resolution

Photosystem II is a multisubunit enzyme complex involved in plant photosynthesis. It uses solar energy to catalyse the breakdown of water to reducing equivalents and molecular oxygen. Native photosystem II comprises more than 25 different subunits, and has a relative molecular mass of more than 600K. Here we report the three-dimensional structure of a photosystem II subcomplex, containing the proteins D1, D2, CP47 and cytochrome b-559, determined by electron crystallography. This CP47 reaction centre, which has a relative molecular mass of 160K, can perform light-mediated energy and electron-transfer reactions but is unable to oxidize water. The complex contains 23 transmembrane alpha-helices, of which 16 have been assigned to the D1, D2 and CP47 proteins. The arrangement of these helices is remarkably similar to that of the helices in the reaction centres of purple bacteria and of plant photosystem I, indicating a common evolutionary origin for these assemblies. The map suggests that redox cofactors in the D1-D2 complex are located in positions analogous to those in the bacterial reaction centre, but the distance between the chlorophylls corresponding to the bacterial 'special pair' is significantly larger.

Comparison of Helicobacter pylori infection between Fukuoka, Japan and Chinju, Korea

BACKGROUND

Helicobacter pylori is the causative agent of type B chronic gastritis, and plays a major role in the pathogenesis of gastroduodenal ulcer and gastric cancer. Because gastric cancer has been the leading cause of cancer mortality in Japan and Korea, we conducted a seroepidemiological study to estimate the prevalence of H. pylori infection in Japan and Korea in order to explain the current change in the gastric cancer incidences between two countries.

MATERIALS AND METHODS

Samples used for this study included 1204 sera from Chinju, Korea and 580 sera from Fukuoka, Japan. Immunoblotting, using a sonicated crude H. pylori antigen and 1:5 dilution of serum, was performed, considering the immunoblot shows reactivity to the 120 Kd antigen of H. pylori as a specific marker of H. pylori infection.

RESULTS

Seroepidemiology data from Fukuoka, Japan showed a prevalence of H. pylori infection of 20% before school age, 40% by teenage years, and over 80% beyond 20 years of age. Seroepidemiology data from Chinju, Korea, showed a 50% infection rate in preschool ages, and over 80% prevalence rate after 7 years of age.

CONCLUSIONS

Lower rates of childhood H. pylori infection in Fukuoka may explain the recent decline and shift in the incidence of stomach cancer in Japan, supporting the hypothesis that H. pylori is a major determinant in the pathogenesis of stomach cancer.

Molecular cloning of a novel potassium-dependent sodium-calcium exchanger from rat brain

We have isolated a novel cDNA clone from rat cerebral cortex encoding a protein of 670 amino acids (NCKX2) that has significant similarity to the 1199-amino acid-long Na/Ca-K exchanger of bovine rod outer segment (NCKX1). NCKX2 transcripts are 10.5 kilobase pairs in length and are expressed abundantly in neurons throughout the brain and with much lower abundance in selected other tissues. The predicted topology of the rat NCKX2 protein is very similar to that of bovine NCKX1, beginning with a solitary transmembrane segment (M0), which is removed as a "signal peptide" in bovine NCKX1, an extracellular loop, a cluster of five transmembrane spanning segments (M1 to M5), a long cytoplasmic loop, and a final hydrophobic cluster (M6 to M11). Within the hydrophobic clusters, rat NCKX2 shares 80% identity and 91% similarity with bovine NCKX1. The two larger hydrophilic loops are much shorter in NCKX2 than in NCKX1, accounting largely for the difference in length between the two proteins, and are dissimilar in sequence except for a 32-amino acid stretch with 69% identity in the cytosolic loop. NCKX2 was epitope-tagged in the extracellular domain and was shown to be expressed at the surface of transfected HEK cells. Analysis of NCKX2 function by fluorescent imaging of fura-2-loaded transfected cells demonstrated that NCKX2 is a potassium-dependent sodium/calcium exchanger.

Construction of a Helicobacter pylori-Escherichia coli shuttle vector for gene transfer in Helicobacter pylori

In this study, a Helicobacter pylori-Escherichia coli shuttle vector was constructed for transferring DNA into H. pylori. The smallest cryptic plasmid (1.2 kb), pHP489, among those harbored by 77 H. pylori isolates was selected as a base replicon for constructing vectors. HindIII-digested pHP489 was ligated with a kanamycin resistance gene [aph(3')-III], which originated from Campylobacter jejuni, to produce the recombinant plasmid pHP489K. pHP489K was efficiently transformed into and stably maintained in H. pylori strains. The shuttle vector pBHP489K (3.6 kb) was constructed by the recombination of pHP489, ColE1, and aph(3')-III sequences. pBHP489K was reciprocally transformed into and maintained in both H. pylori and E. coli. Introduction of the shuttle vector clone DNA (pBHP489K/AB; 6.7 kb), containing the ureA and ureB genes of H. pylori, into urease-negative mutants of H. pylori led to the restoration of their urease activity. The transformants were confirmed to contain the incoming plasmid DNA. pBHP489K satisfied the requirements for an H. pylori-E. coli shuttle vector, implying that it might be a useful vector for investigating pathogenicity and restriction-modification systems of H. pylori.

Monoclonal antibodies against Helicobacter pylori cross-react with human tissue

BACKGROUND

H. pylori is a causative agent of chronic gastritis. However, the pathogenic mechanism by which H. pylori induces chronic inflammation and epithelial injuries in the gastric and duodenal mucosa is not well known. Investigators have recently reported that some monoclonal antibodies against H. pylori cross-react with the gastric epithelial cells. So, there exists the possibility that the autoimmune mechanism may be involved in the pathogenesis of chronic gastritis caused by H. pylori. The purpose of his study is to investigate whether the antibodies against H. pylori react with human tissues or not, using a large panel of monoclonal antibodies.

MATERIALS AND METHODS

Two hundred and fourteen monoclonal antibodies against H. pylori were produced. An immunohistochemical staining of human tissues, including H. pylori-infected gastric mucosa, was performed using the antibodies.

RESULTS

Of 214 monoclonal antibodies, 71 antibodies reacted with H. pylori in the gastric mucosa. Of 71 antibodies, 25 antibodies also reacted with gastric epithelial cells, 11 antibodies reacted with ductal cells of the salivary gland, 11 antibodies reacted with renal tubular cells, and 8 antibodies reacted with duodenal epithelial cells. The antibodies which showed cross-reactivity with gastric epithelial cells included those against urease, flagella, lipopolysaccharide, and heat shock protein of H. pylori.

CONCLUSIONS

It is believed that the autoimmune reaction might be involved in the pathogenesis of chronic gastritis due to H. pylori infection, and that the autoimmune reaction induced by H. pylori infection might also be involved in the pathogenesis of various diseases in other organs.

Postresuscitation left ventricular systolic and diastolic dysfunction. Treatment with dobutamine

BACKGROUND

Global left ventricular dysfunction after successful resuscitation is well documented and appears to be a major contributing factor in limiting long-term survival after initial recovery from out-of-hospital sudden cardiac death. Treatment of such postresuscitation myocardial dysfunction has not been examined previously.

METHODS AND RESULTS

Systolic and diastolic parameters of left ventricular function were measured in 27 swine before and after successful resuscitation from prolonged ventricular fibrillation cardiac arrest. Dobutamine infusions (10 micrograms.kg-1.min-1 in 14 animals or 5 micrograms.kg-1.min-1 in 5 animals) begun 15 minutes after resuscitation were compared with controls receiving no treatment (8 animals). The marked deterioration in systolic and diastolic left ventricular function seen in the control group after resuscitation was ameliorated in the dobutamine-treated animals. Left ventricular ejection fraction fell from a prearrest 58 +/- 3% to 25 +/- 3% at 5 hours after resuscitation in the control group but remained unchanged in the dobutamine (10 micrograms.kg-1.min-1) group (52 +/- 1% prearrest and 55 +/- 3% at 5 hours after resuscitation). Measurement of the constant of isovolumic relaxation of the left ventricle (tau) demonstrated a similar benefit of the dobutamine infusion for overcoming postresuscitation diastolic dysfunction. The tau rose in the controls from 28 +/- 1 milliseconds (ms) prearrest to 41 +/- 3 ms at 5 hours after resuscitation whereas it remained constant in the dobutamine-treated animals (31 +/- 1 ms prearrest and 31 +/- 5 ms at 5 hours after resuscitation).

CONCLUSIONS

Dobutamine begun within 15 minutes of successful resuscitation can successfully overcome the global systolic and diastolic left ventricular dysfunction resulting from prolonged cardiac arrest and cardiopulmonary resuscitation.

The bifunctional protein DCoH modulates interactions of the homeodomain transcription factor HNF1 with nucleic acids

The hepatocyte nuclear factor-1 (HNF1) is a homeodomain transcription factor that binds DNA as a dimer. HNF1 dimers associate with two molecules of DCoH, a bifunctional protein that also has an enzymatic function in the tetrahydrobiopterin regeneration, to form stable heterotetramers also capable of DNA binding. Employing purified, recombinant HNF1, HNF1/DCoH heterotetramers and DCoH homotetramers we investigated whether DCoH affects interactions of HNF1 with nucleic acids. Although we detected no direct binding of DCoH to DNA or RNA, DCoH stabilized HNF1/DNA complexes and promoted interactions with sub-optimal DNA target sequences such as the human alpha1-antitrypsin TATA box region. Importantly, we also observed interactions of HNF1 with RNA, but these interactions were completely abolished when HNF1 was complexed with DCoH. Interestingly, DCoH retains its enzymatic activity while complexed with HNF1. Our results document intermolecular regulation of HNF1 binding to nucleic acids by DCoH.

Pathogenesis and prevention of stomach cancer

In many Western developed countries, the incidence of stomach cancer has declined dramatically. This decrease was an extraordinary, "unplanned triumph", especially when compared to other cancers. Stomach cancer is still the most prevalent malignant tumor in Korea. Most Koreans carry Helicobacter pylori in their stomach. Thus, a new hypothesis, based on the relationship between the host and Helicobacter pylori, is presented as the carcinogenesis of human stomach cancer. The reasons for why the N-nitrosamide hypothesis should be dismissed as the etiology of stomach cancer, and why the contemporarily available principles and practice of intervention strategies to rapidly decrease the surprisingly high prevalence rate of Helicobacter pylori infection are impractical at this moment, are explained. In order to introduce an alternative provisional strategy of the "planned triumph" for the population vulnerable to stomach cancer, vitamin C is defined as an anti-inflammatory agent on the basis of the pathogenesis of Helicobacter pylori infection.

Myocardial dysfunction after resuscitation from cardiac arrest: an example of global myocardial stunning

OBJECTIVES

This study investigated the effect of prolonged cardiac arrest and subsequent cardiopulmonary resuscitation on left ventricular systolic and diastolic function.

BACKGROUND

Cardiac arrest from ventricular fibrillation results in cessation of forward blood flow, including myocardial blood flow. During cardiopulmonary resuscitation, myocardial blood flow remains suboptimal. Once the heart is defibrillated and successful resuscitation achieved, reversible myocardial dysfunction, or "stunning," may occur. The magnitude and time course of myocardial stunning from cardiac arrest is unknown.

METHODS

Twenty-eight domestic swine (26 +/- 1 kg) were studied with both invasive and noninvasive measurements of ventricular function before and after 10 or 15 min of untreated cardiac arrest. Contrast left ventriculograms, ventricular pressures, cardiac output, isovolumetric relaxation time (tau) and transthoracic Doppler-echocardiographic studies were obtained.

RESULTS

Twenty-three of 28 animals were successfully resuscitated and postresuscitation data obtained. Left ventricular ejection fraction showed a significant reduction 30 min after resuscitation (p < 0.05). Regional wall motion analysis revealed diffuse, global left ventricular systolic dysfunction. Left ventricular end-diastolic pressure increased significantly in the postresuscitation period (p < 0.05). Isovolumetric relaxation time (tau) was significantly increased over baseline by 2 h after resuscitation (p < 0.05). Similar findings were noted with the Doppler-echocardiographic analysis, including a reduction in fractional shortening (p < 0.05), a reduction in mitral valve deceleration time (p < 0.05) and an increase in left ventricular isovolumetric relaxation time at 5 h after resuscitation (p < 0.05> By 24 h, these invasive and noninvasive variables of systolic and diastolic left ventricular function had begun to improve. At 48 h, all measures of left ventricular function had returned to baseline levels.

CONCLUSIONS

Myocardial systolic and diastolic dysfunction is severe after 10 to 15 min of untreated cardiac arrest and successful resuscitation. Full recovery of this postresuscitation myocardial stunning is seen by 48 h in this experimental model of ventricular fibrillation cardiac arrest.

Increased oxidative DNA damage in Helicobacter pylori-infected human gastric mucosa

Helicobacter pylori causes type B gastritis. It shows strong association with the development of gastric carcinoma. A plausible hypothesis for the missing link between H. pylori infection and gastric carcinogenesis involves oxygen free radical-induced DNA damage. To test this hypothesis, we compared the amount of 9-hydroxydeoxyguanosine, a marker for oxygen free radical-induced DNA damage, in the DNA of human gastric mucosa with and without H. pylori infection. Gastric antral biopsies were taken from pediatric patients and volunteers to select H. pylori-positive and H. pylori-negative specimens. The 8-hydroxydeoxyguanosine content of the gastric mucosal DNA was measured after H. pylori-positive and H. pylori-negative volunteers were identified. The increased level of oxidative DNA damage suggests the mechanistic link between H. pylori infection and gastric carcinoma.

Effects of rebamipide on gastric cell damage by Helicobacter pylori-stimulated human neutrophils

Helicobacter pylori stimulated human neutrophils to produce oxygen radicals as evidenced by the production of chemiluminescence in the presence of luminol. The capacity of H. pylori to produce oxygen radicals from neutrophils was much higher than that of Escherichia coli and Staphylococcus aureus and is almost as strong as that of PMA. Rebamipide (2-(4-chlorobenzoylamino)-3-[2-(1H)-quinolinon-4-yl] propionic acid) suppressed the chemiluminescence produced by H. pylori-stimulated neutrophils and also suppressed the chemiluminescence produced by a cell-free xanthine/xanthine oxidase reaction with luminol. Thus, it is indicated that this drug has the action of scavenging oxygen radicals. Gastric mucosal cells labelled with a fluorescent dye were damaged by the incubation of the cells with neutrophils and H. pylori, and this damage was protected by rebamipide. The protection of cell damage was ascertained as a decrease in the release of fluorescent dye into the incubation medium and a reduction in the distortion of cell geometry. The data suggest that H. pylori induce human neutrophils to produce oxygen radicals which are responsible for gastric mucosal cell damage and that rebamipide removes the oxygen radicals produced from H. pylori-activated neutrophils and thus reduces the gastric mucosal cell damage. These effects may account for the ulcerogenesis action of H. pylori and for part of the mechanism of the anti-ulcer action of rebamipide.

Antegrade cannulation of radial artery in infants and children

We describe the novel approach of antegrade radial artery cannulation in five pediatric patients after failure of standard retrograde cannulation by percutaneous and cutdown technique. This antegrade cannulation led to successful, reliable continuous blood pressure monitoring and arterial blood sampling without complications. We believe antegrade cannulation can be successfully used when radial arteries are obstructed and retrograde blood flow is observed during failed cutdown attempts at standard retrograde arterial cannulation.

Carbicarb, sodium bicarbonate, and sodium chloride in hypoxic lactic acidosis. Effect on arterial blood gases, lactate concentrations, hemodynamic variables, and myocardial intracellular pH

The effects of Carbicarb, sodium bicarbonate, and sodium chloride on arterial blood gases, lactate concentrations, hemodynamics, and myocardial intracellular pH were compared in hypoxic lactic acidosis with controlled carbon dioxide elimination. Twenty-one young mongrel dogs were anesthetized, mechanically ventilated, and randomly allocated into one of three treatment groups. After hypoxic lactic acidosis was induced and maintained, 2.5 mEq/kg of one of the agents was infused over 30 min. Arterial blood gases, pH, lactate concentrations, and hemodynamic variables were measured immediately prior to the infusion of the agent and 30 min after the infusion was completed. With sodium bicarbonate administration, there was a significant increase in arterial PCO2 as compared to both Carbicarb or sodium chloride administration. With Carbicarb administration, there was a significant increase in arterial pH, base excess, and cardiac index, without a significant increase in arterial lactate concentration as compared to sodium bicarbonate or sodium chloride administration. Stroke volume index was also increased significantly with decreased heart rate. The data suggest that Carbicarb administration in hypoxic lactic acidosis improved hemodynamics compared with sodium bicarbonate or sodium chloride administration. The increased stroke volume and cardiac contractility appear to be due to improved myocardial intracellular pH.

Development of epidemiological method for the Helicobacter pylori by polymerase chain reaction

The polymerase chain reaction was used to develop a method for the detection of Helicobacter pylori, a causative agent of gastritis, as well as for the elucidation of its mode of transmission. A genomic library of Helicobacter pylori DNA in Escherichia coli JM109 was constructed by cloning Hind III-digested DNA fragments into plasmid vector pUC18. The nucleotide sequences from seven recombinant clones were determined and five sets of oligonucleotide primers were synthesized on the basis of the sequences from five clones (B4, B9, B10, C15 and I22). The PCR amplifications with these primers were performed using DNA samples from five strains of Helicobacter pylori, two Campylobacter spp. and eleven species of enteric bacteria. Amplifications of the target DNA fragments in all of 5 strains of Helicobacter pylori were observed from the PCR with primers derived from clone B4, B9, C15 and I22. When the specificity was checked with the DNA samples from 13 other bacteria as template DNA for the PCR, specific amplification that produced the correct size of the target DNA of Helicobacter pylori was shown only in the PCR with primers derived from clone B9 and C15. The detection limit in the PCR amplification, determined by the heat-lysis method, was 500 cells of Helicobacter pylori.

Purification of heat-labile enterotoxin from an enterotoxin from an enterotoxigenic Escherichia coli of human origin by monoclonal immunoaffinity chromatography

Heat-labile enterotoxin (LT) was purified from an enterotoxigenic Escherichia coli 015H11 of human origin. The purification steps included French pressure cell disruption of the bacteria, salting-out, DEAE-Sephacel on chromatography. Application of this procedure resulted in a 95.1-fold purification of LT with a yield of 19.9% as determined by rabbit ileal loop assay. The final LT preparation showed only one protein-staining band on polyacrylamide gel electrophoresis, indicating that the purified LT was homogeneous.

Individualized surgical management of complete atrioventricular canal

In a 5 year interval 46 children with complete atrioventricular canal (CAVC) required 51 operations. Thirty-two children underwent correction; nine received surgical palliation. The ages of the children undergoing correction ranged from 4 months to 14.6 years (mean 4.2 years); eight were less than 1 year old. Weights ranged from 4.1 kg to 39 kg (mean 13.5 kg); 15 weighted less than 10 kg. Ten had undergone previous palliation (seven by pulmonary artery band; three by shunt). There were no early deaths and two late deaths. One infant required mitral replacement at correction; two required subsequent mitral replacement. The ages of the children undergoing palliation ranged from 8 days to 1.34 years (mean 5.8 months); 16 were less than 1 year old. Weights ranged from 2.5 kg to 8.5 kg (mean 4.4 kg); 14 weighted less than 5 kg. Operations included pulmonary artery banding in 14, shunt creation in four, and pericardial enlargement of the right ventricular outflow tract in one. One death occurred 5 days after pulmonary artery banding in an infant with unrecognized coarctation. One late death occurred several months after the creation of a second shunt in a child with severe tetralogy of Fallot and hypoplastic pulmonary arteries. Forty-two (91%) of these children were alive at the time of this review. The outcome in these 46 patients supports individualized choice of initial operation (palliation versus correction) based upon clinical condition, weight, and associated anomalies. The pulmonary artery is banded in infants less than 4 to 5 kg; larger infants and children undergo correction primarily.