Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
260
result(s) for
"Morgan, Douglas R"
Sort by:
High prevalence of gastric intestinal metaplasia detected by confocal laser endomicroscopy in Zambian adults
by
Zyambo, Kanekwa
,
Morgan, Douglas R.
,
Kayamba, Violet
in
Achlorhydria - metabolism
,
Adult
,
Adults
2017
Confocal laser endomicroscopy (CLE) may increase the detection of gastric premalignant lesions, and facilitate targeted biopsies for histology. The study aim was to analyse premalignant lesions in Zambian adults using CLE.
Using CLE and histology we analysed the antral mucosa for gastric premalignant lesions in asymptomatic adults living with HIV and in HIV seronegative adults. Fasting gastric pH and the presence of Helicobacter pylori (H. pylori) were also evaluated.
We enrolled 84 HIV seropositive participants (median age 43 years; 55 (65%) female), of whom 32 (38%) were anti-retroviral therapy (ART)-naïve. Also enrolled were 22 HIV seronegative controls (median age 39 years, 12 (55%) females). Hypochlorhydria was found in 48 (57%) HIV positive and 8 (38%) HIV negative controls (P = 0.14). Detection of gastric intestinal metaplasia (GIM) was higher (P = 0.007) using CLE (49, 54%) than histology (9, 9%) and, using CLE, GIM was similar between HIV positive (41, 60%) and negative groups (8, 36%; P = 0.08). Gastric luminal fluorescein leakage was significantly associated with the presence of GIM [OR 8.2; 95% CI 2.5-31, P<0.001].
CLE is useful for the detection of GIM, and luminal fluorescein leakage may represent a novel CLE marker for GIM. GIM is common in Zambian adults, and is highly prevalent irrespective of HIV infection or use of ART.
Journal Article
Wood cookstove use is associated with gastric cancer in Central America and mediated by host genetics
by
Dominguez, Ricardo L.
,
Waterboer, Tim
,
Williams, Scott M.
in
631/208/205
,
631/208/68
,
631/326/421
2023
Biomass cookstove food preparation is linked to aero-digestive cancers, mediated by ingested and inhaled carcinogens (e.g., heterocyclic amines, and polycyclic aromatic hydrocarbons). We investigated the association between gastric adenocarcinoma, wood cookstove use,
H. pylori
CagA infection and risk modification by variants in genes that metabolize and affect the internal dose of carcinogens. We conducted a population-based, case–control study (814 incident cases, 1049 controls) in rural Honduras, a high-incidence region with a homogeneous diet and endemic
H. pylori
infection, primarily with the high-risk CagA genotype. We investigated factors including wood cookstove use,
H. pylori
CagA serostatus, and 15 variants from 7 metabolizing genes, and the interactions between wood stove use and the genetic variants. Male sex (OR 2.0, 1.6–2.6), age (OR 1.04, 1.03–1.05), wood cookstove use (OR 2.3, 1.6–3.3), and CagA serostatus (OR 3.5, 2.4–5.1) and two SNPs in
CYP1B1
(rs1800440 and rs1056836) were independently associated with gastric cancer in multivariate analysis. In the final multivariate model, a highly significant interaction (OR 3.1, 1.2–7.8) was noted between wood cookstove use and the rs1800440 metabolizing genotype, highlighting an important gene-environment interaction. Lifetime wood cookstove use associates with gastric cancer risk in the high-incidence regions of Central America, and the association is dependent on the rs1800440 genotype in
CYP1B1
.
H. pylori
CagA infection, wood cookstove use and the rs1800440 genotype, all of which are highly prevalent, informs who is at greatest risk from biomass cookstove use.
Journal Article
The Burden of Gastrointestinal and Liver Diseases, 2006
by
Morgan, Douglas R
,
Thiny, Michelle T
,
Hansen, Richard A
in
Biological and medical sciences
,
Female
,
Gastroenterology
2006
Digestive and liver diseases are a source of significant morbidity, mortality, and health-care costs for the U.S. population. An annual report of the toll of these diseases could be helpful to clinicians, policymakers, and researchers.
To describe the epidemiology of gastrointestinal and liver diseases in the United States using data from privately and publicly held databases.
We collected data from the National Center for Health Statistics, the National Ambulatory Medical Care Survey, the National Inpatient Sample, the Centers for Disease Control and Prevention, and the National Cancer Institute, as well as proprietary pharmaceutical databases to construct a report on the impact of gastrointestinal and liver diseases on the U.S. population. We compiled information on causes of death, hospitalization, clinic visits, cancer incidence, and mortality and infectious disease incidence from these databases, and extracted data specific to gastrointestinal diseases. Because of the high costs associated with medications used to treat gastrointestinal diseases, we also include in this year's report a special section on pharmacoepidemiology and pharmacoeconomics.
Colorectal cancer continues to be the leading cause of GI-related death, although the data indicate a downward trend in deaths. Abdominal pain, diarrhea, vomiting, and nausea are the most common GI symptoms precipitating a visit to the physician, and GERD is the most common GI-related diagnosis given in office visits. Chest pain not specified to be cardiac in origin is the most common cause of inpatient admission possibly related to GI disease, with cholelithiasis and pancreatitis following. Americans spend in excess of US dollars 10 billion/yr on proton pump inhibitors (PPIs), and two of the top five selling drugs in the United States are PPIs. Trends in PPI use demonstrate turbulent changes, likely reflecting both new drug entries into the field, as well as drug marketing. The number of PPI prescriptions/yr in the United States has doubled since 1999. Twenty-three drugs used for gastrointestinal diseases are among the top 200 generic drugs used in the United States.
Gastrointestinal and liver diseases are significant contributors to the morbidity, mortality, and health-care expenditures of the U.S. population.
Journal Article
Epidemiology of Helicobacter pylori infection in six Latin American countries (SWOG Trial S0701)
2013
Objective: To investigate the potential determinants of Helicobacter pylori infection between adults 21–65 years old. Methods: Data are from the initial screening visit of a randomized clinical trial of three antibiotic regimens to eradicate H. pylori, conducted in seven sites (Santiago—Chile, Túquerres—Colombia, Guanacaste—Costa Rica, Copán—Honduras, Obregón and Tapachula—México, León—Nicaragua). Thousand eight hundred and fifty-nine adults from the general population were screened for H. pylori infection using an urea breath test (UBT) and were interviewed to assess socioeconomic-, demographic-, and symptom-related characteristics. Logistic regression was used to assess the relationship between these characteristics and H. pylori positivity at enrollment. Results: Among the 1,852 eligible participants for whom a conclusive UBT result was obtained, H. pylori prevalence was 79.4 %, ranging from 70.1 to 84.7 % among the seven centers. Prevalence did not differ by sex (female: 78.4, male: 80.9; p = 0.20) or age (p = 0.08). H. pylori positivity increased with increasing number of siblings (p trend <0.0001). Participants with education beyond 12 years were less likely to be UBT-positive (OR 0.4: 0.3–0.6, compared to participants with 0–6 years of schooling) as were those employed outside the home (OR 0.7: 0.6–1.0). Odds of H. pylori infection increased with the presence of certain living conditions during childhood including having lived in a household with an earth floor (OR 1.8:1.4–2.4), lack of indoor plumbing (OR 1.3: 1.0–1.8) and crowding (OR 1.4: 1.0–1.8, for having more than two persons per bedroom). Regarding current household conditions, living with more than 3 children in the household (OR 1.7: 1.2–2.5) and crowding (OR 1.8: 1.3–2.3) were associated with H. pylori infection. Conclusions: The prevalence of H. pylori in adults was high and differed significantly among the six Latin American countries studied (p < 0.001). Our findings confirm the strong link between poor socioeconomic conditions and H. pylori infection.
Journal Article
14-day triple, 5-day concomitant, and 10-day sequential therapies for Helicobacter pylori infection in seven Latin American sites: a randomised trial
by
Crowley, John J
,
Torres, Javier
,
Herrero, Rolando
in
2-Pyridinylmethylsulfinylbenzimidazoles - administration & dosage
,
Adult
,
Aged
2011
Evidence from Europe, Asia, and North America suggests that standard three-drug regimens of a proton-pump inhibitor plus amoxicillin and clarithromycin are significantly less effective for eradication of
Helicobacter pylori infection than are 5-day concomitant and 10-day sequential four-drug regimens that include a nitroimidazole. These four-drug regimens also entail fewer antibiotic doses than do three-drug regimens and thus could be suitable for eradication programmes in low-resource settings. Few studies in Latin America have been done, where the burden of
H pylori-associated diseases is high. We therefore did a randomised trial in Latin America comparing the effectiveness of four-drug regimens given concomitantly or sequentially with that of a standard 14-day regimen of triple therapy.
Between September, 2009, and June, 2010, we did a randomised trial of empiric 14-day triple, 5-day concomitant, and 10-day sequential therapies for
H pylori in seven Latin American sites: Chile, Colombia, Costa Rica, Honduras, Nicaragua, and Mexico (two sites). Participants aged 21–65 years who tested positive for
H pylori by a urea breath test were randomly assigned by a central computer using a dynamic balancing procedure to: 14 days of lansoprazole, amoxicillin, and clarithromycin (standard therapy); 5 days of lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant therapy); or 5 days of lansoprazole and amoxicillin followed by 5 days of lansoprazole, clarithromycin, and metronidazole (sequential therapy). Eradication was assessed by urea breath test 6–8 weeks after randomisation. The trial was not masked. Our primary outcome was probablity of
H pylori eradication. Our analysis was by intention to treat. This trial is registered with
ClinicalTrials.gov, registration number
NCT01061437.
1463 participants aged 21–65 years were randomly allocated a treatment: 488 were treated with 14-day standard therapy, 489 with 5-day concomitant therapy, and 486 with 10-day sequential therapy. The probability of eradication with standard therapy was 82·2% (401 of 488), which was 8·6% higher (95% adjusted CI 2·6–14·5) than with concomitant therapy (73·6% [360 of 489]) and 5·6% higher (–0·04% to 11·6) than with sequential therapy (76·5% [372 of 486]). Neither four-drug regimen was significantly better than standard triple therapy in any of the seven sites.
Standard 14-day triple-drug therapy is preferable to 5-day concomitant or 10-day sequential four-drug regimens as empiric therapy for
H pylori infection in diverse Latin American populations.
Bill & Melinda Gates Foundation, US National Institutes of Health.
Journal Article
ACG Clinical Guideline: Treatment of Helicobacter pylori Infection
by
Howden, Colin W.
,
Grover, Shilpa
,
Greer, Katarina B.
in
Anti-Bacterial Agents - therapeutic use
,
Antibiotics
,
Bacterial infections
2024
ABSTRACTHelicobacter pylori is a prevalent, global infectious disease that causes dyspepsia, peptic ulcer disease, and gastric cancer. The American College of Gastroenterology commissioned this clinical practice guideline (CPG) to inform the evidence-based management of patients with H. pylori infection in North America. This CPG used Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology to systematically analyze 11 Population, Intervention, Comparison, and Outcome questions and generate recommendations. Where evidence was insufficient or the topic did not lend itself to GRADE, expert consensus was used to create 6 key concepts. For treatment-naive patients with H. pylori infection, bismuth quadruple therapy (BQT) for 14 days is the preferred regimen when antibiotic susceptibility is unknown. Rifabutin triple therapy or potassium-competitive acid blocker dual therapy for 14 days is a suitable empiric alternative in patients without penicillin allergy. In treatment-experienced patients with persistent H. pylori infection, \"optimized\" BQT for 14 days is preferred for those who have not been treated with optimized BQT previously and for whom antibiotic susceptibility is unknown. In patients previously treated with optimized BQT, rifabutin triple therapy for 14 days is a suitable empiric alternative. Salvage regimens containing clarithromycin or levofloxacin should only be used if antibiotic susceptibility is confirmed. The CPG also addresses who to test, the need for universal post-treatment test-of-cure, and the current evidence regarding antibiotic susceptibility testing and its role in guiding the choice of initial and salvage treatment. The CPG concludes with a discussion of proposed research priorities to address knowledge gaps and inform future management recommendations in patients with H. pylori infection from North America.
Journal Article
A 500-year tale of co-evolution, adaptation, and virulence: Helicobacter pylori in the Americas
2021
Helicobacter pylori
is a common component of the human stomach microbiota, possibly dating back to the speciation of
Homo sapiens
. A history of pathogen evolution in allopatry has led to the development of genetically distinct
H. pylori
subpopulations, associated with different human populations, and more recent admixture among
H. pylori
subpopulations can provide information about human migrations. However, little is known about the degree to which some
H. pylori
genes are conserved in the face of admixture, potentially indicating host adaptation, or how virulence genes spread among different populations. We analyzed
H. pylori
genomes from 14 countries in the Americas, strains from the Iberian Peninsula, and public genomes from Europe, Africa, and Asia, to investigate how admixture varies across different regions and gene families. Whole-genome analyses of 723
H. pylori
strains from around the world showed evidence of frequent admixture in the American strains with a complex mosaic of contributions from
H. pylori
populations originating in the Americas as well as other continents. Despite the complex admixture, distinctive genomic fingerprints were identified for each region, revealing novel American
H. pylori
subpopulations. A pan-genome Fst analysis showed that variation in virulence genes had the strongest fixation in America, compared with non-American populations, and that much of the variation constituted non-synonymous substitutions in functional domains. Network analyses suggest that these virulence genes have followed unique evolutionary paths in the American populations, spreading into different genetic backgrounds, potentially contributing to the high risk of gastric cancer in the region.
Journal Article
Epstein-Barr Virus Infection Is Common in Inflamed Gastrointestinal Mucosa
2012
Background and Aims
Epstein-Barr virus (EBV) is present in the malignant epithelial cells of 10% of all gastric adenocarcinomas; however, localization of the virus in normal gastrointestinal mucosa is largely unexplored. In the present study, we measured EBV DNA and localized viral gene products in gastritis specimens (
n
= 89), normal gastric and colonic mucosa (
n
= 14), Crohn’s disease (
n
= 9), and ulcerative colitis (
n
= 11) tissues.
Methods
A battery of sensitive and specific quantitative polymerase chain reactions targeted six disparate regions of the EBV genome:
BamH1
W, EBNA1, LMP1, LMP2, BZLF1,
and
EBER1
. EBV infection was localized by
EBV
-
encoded RNA
(
EBER
) in situ hybridization and by immunohistochemical stains for viral latent proteins LMP1 and LMP2 and for viral lytic proteins BMRF1 and BZLF1. B lymphocytes were identified using CD20 immunostains.
Results
EBV DNA was essentially undetectable in normal gastric mucosa but was present in 46% of gastritis lesions, 44% of normal colonic mucosa, 55% of Crohn’s disease, and 64% of ulcerative colitis samples. Levels of EBV DNA exceeded what would be expected based on the numbers of B lymphocytes in inflamed tissues, suggesting that EBV is preferentially localized to inflammatory gastrointestinal lesions. Histochemical staining revealed
EBER
expression in lymphoid cells of some PCR-positive lesions. The viral lytic viral proteins, BMRF1 and BZLF1, were expressed in lymphoid cells of two ulcerative colitis tissues, both of which had relatively high viral loads by quantitative PCR.
Conclusion
EBV-infected lymphocytes are frequently present in inflamed gastric and colonic mucosa. Active viral replication in some lesions raises the possibility of virus-related perpetuation of gastrointestinal inflammation.
Journal Article
Racial/ethnic disparities in gastric cancer: A 15‐year population‐based analysis
by
Perez‐Portocarrero, Luis
,
Cruz‐Correa, Marcia
,
Vargas‐Ramos, Yimari
in
Adenomatous polyposis coli
,
Cancer screening
,
Epidemiology
2023
Background and aims: Disparities in gastric cancer incidence and mortality have been reported among ethnic/racial groups. While gastric cancer is not common in the U.S., it is among the top 10 causes of cancer‐related death among Hispanics living in Puerto Rico (PRH). This study compared gastric cancer incidence rates during a 15‐year period (2002–2006, 2007–2011, and 2012–2016) between PRH and racial/ethnic groups in the mainland U.S., including Non‐Hispanic Whites (NHW), Non‐Hispanics Blacks (NHB), Hispanics (USH), and Non‐Hispanic Asian or Pacific Islanders (NHAPI). Methods Primary gastric cancer cases (ICD‐O‐3 codes C16.0 to C16.9) from the Puerto Rico Central Cancer Registry and SEER diagnosed from January 1, 2002 to December 31, 2016 were included in the analysis. The Joinpoint Regression Program and standardized rate ratios were used to estimate Annual Percent Changes (APC) and differences in gastric cancer incidence among racial/ethnic groups, respectively. Results Our analysis included 83,369 gastric cancer cases (PRH n = 4202; NHW n = 43,164; NHB n = 10,414; NHAPI n = 11,548; USH n = 14,041). USH had the highest number of cases among individuals <50 years, whereas NHW and PRH had the highest percentage among individuals ≥50 years. PRH and USH were the only groups with increasing APCs among individuals <50 years. Conclusions Gastric cancer continues to be a common cancer among PRH, despite the overall decrease in incidence among other racial/ethnic groups. Studies evaluating the gastric cancer risk factors among high‐risk groups are necessary to establish health policy and modify gastric cancer screening algorithms among Hispanics. Among Hispanics, gastric tumors continue to be commonly diagnosed; only 32% of individuals diagnosed with this malignancy survive more than 5 years. An increase in gastric cancer among individuals younger than 50 years and diagnosis at regional (more advanced) stages was observed when comparing Hispanics living in Puerto Rico to other racial/ethnic groups on the U.S. mainland. Our findings underscore the importance of evaluating gastric cancer risk factors among diverse, high‐risk groups, such as Hispanics, in order to develop tailored prevention and risk stratification strategies.
Journal Article
Duodenal Ulceration following Holmium Laser Lithotripsy
2019
The epidemiology of peptic ulcer disease (PUD) has changed considerably in the last several decades. Previously a chronic disease characterized by frequent recurrences with a high rate of surgical interventions, it is now largely a self-limited disease that is medically managed. The role of acid suppression was widely recognized as being important in the pathogenesis of PUD in the 19th century, while it was not until the 1980s and 1990s that the importance of Helicobacter pylori infection was identified. Today, PUD is largely caused by either H. pylori infection or nonsteroidal anti-inflammatory drug use. However, other less common etiologies of this disease are becoming more relevant as the prevalence of H. pylori decreases and proton pump inhibitor therapy is increasingly common. Here, we report a case of duodenal ulceration following bilateral rigid ureteroscopy with holmium laser lithotripsy.
Journal Article