Alan J. Parkinson

The King's College

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Michael G. Bruce

Centers for Disease Control and Prevention

Lisa Bulkow

National Center for Emerging and Zoonotic Infectious Diseases

Brian J. McMahon

Centers for Disease Control and Prevention

Thomas W. Hennessy

Centers for Disease Control and Prevention

Debby Hurlburt

National Center for Emerging and Zoonotic Infectious Diseases

Jay C. Butler

Centers for Disease Control and Prevention

Tammy Zulz

Centers for Disease Control and Prevention

Karen Rudolph

Centers for Disease Control and Prevention

Rosalyn Singleton

Centers for Disease Control and Prevention

Alisa Reasonover

Centers for Disease Control and Prevention

Cooperative Institutions

Centers for Disease Control and Prevention

119

National Center for Infectious Diseases

Alaska Native Medical Center

National Center for Emerging and Zoonotic Infectious Diseases

Johns Hopkins University

Alaska Native Tribal Health Consortium

Indian Health Service

The Centers

Emory University

United States Department of Health and Human Services

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Characterization of Helicobacter pylori cagA andvacAGenotypes among Alaskans and Their Correlation with Clinical Disease

Journal of Clinical Microbiology (2011)

Karen Miernyk Julie Morris Dana Bruden Brian J. McMahon Debby Hurlburt

Helicobacter pylori infection is common in Alaska. The development of severe H. pylori disease is partially determined by the virulence of the infecting strain. Here we present vacA and cagA genotype data for H. pylori strains isolated from Alaskans and their correlation with clinical disease. We enrolled patients scheduled for esophagogastroduodenoscopy and positive for H. pylori infection. Gastric biopsy specimens from the stomach antrum and fundus were cultured. We performed PCR analysis of the H. pylori vacA gene and for the presence of the cagA gene and cagA empty site. We genotyped 515 H. pylori samples from 220 Native and 66 non-Native Alaskans. We detected the cagA gene in 242/286 (85%) persons; of 222 strains that could be subtyped, 95% (212) were non-Asian cagA and 3% (6) were East Asian cagA. After removing mixed infections (n = 17), 83% of H. pylori strains had either the vacA s1m1 (120/269) or s2m2 (103/269) genotype. Sixty-six percent (68/103) of H. pylori strains with the vacA s2m2 genotype also contained the cagA gene. Infection with an H. pylori strain having the cagA gene or vacA s1m1 genotype (compared with s1m2 and s2m2) was associated with a decreased risk of esophagitis (P = 0.003 and 0.0003, respectively). Infection with an H. pylori strain having the vacA s1m1 genotype (compared with s1m2 and s2m2) was associated with an increased risk of peptic ulcer disease (PUD) (P = 0.003). The majority of H. pylori strains in this study carried the non-Asian cagA gene and either the vacA s1m1 or s2m2 genotype. A majority of H. pylori strains with the vacA s2m2 genotype also contained the cagA gene. There was an association of H. pylori genotype with esophagitis and PUD.

CagA

Spirillaceae

10.1128/jcm.00469-11

Cite

Citations (52)

Reinfection after successful eradication of Helicobacter pylori: a 2‐year prospective study in Alaska Natives

Alimentary Pharmacology & Therapeutics (2006)

Brian J. McMahon Michael G. Bruce Thomas W. Hennessy Dana L. Bruden Frank Sacco

Summary Background Limited information exists regarding risk factors for reinfection after cure of Helicobacter pylori infection. Aim To determine the 2‐year reinfection rate of H. pylori in a cohort of urban Alaska Natives. Methods Participants over 18 years of age undergoing oesophagogastroduodenoscopy had 13 C urea breath test, culture, CLOtest and histology performed. Those diagnosed with H. pylori who tested urea breath test‐negative at 8 weeks after treatment were followed prospectively at 4 months, 6 months, 1 year and 2 years. Subjects experiencing H. pylori reinfection as defined by a positive urea breath test were compared with those who did not become reinfected using univariable and multivariable analysis. Risk of reinfection over time was estimated by the Kaplan–Meier method. Results Helicobacter pylori reinfection occurred in 14 of 98 subjects successfully treated. The cumulative reinfection rate was 5.1% (95% CI: 0.7%–9.5%) at 4 months, 7.2% (2.0–12.3%) at 6 months, 10.3% (4.2–16.3%) at 1‐year and 14.5% (7.5–21.6%) at 2 years. In multivariable analysis, a history of previous peptic ulcer disease or presence of ulcer at time of study oesophagogastroduodenoscopy were the only risk factors associated with reinfection ( P = 0.01). Conclusions Based on the findings from our study, subjects with a history of or current peptic ulcer disease should be followed, after successful treatment for H. pylori , with periodic urea breath test to detect reinfection, as reinfection would put them at high risk for ulcer recurrence.

Urea breath test

10.1111/j.1365-2036.2006.02880.x

Cite

Citations (46)

Comparative Study of 125 I- and [ 3 H]Acetate-Labeled Antibodies in Detecting Iridescent Viruses

Applied Microbiology (1974)

S. L. Bilimoria Alan J. Parkinson J. Kalmakoff

Radioimmunoassays for detecting cell-associated or released virus are described using either 125 I- or [ 3 H]acetate-labeled antibodies. In the first assay system, antigen-antibody complexes were separated from free antibody by centrifugation. Sensitivities of 0.1 μg of iridescent virus could be achieved with either 125 I- or [ 3 H]acetate-labeled antibody. In the second assay, the antigen was fixed to cover-slip cell cultures, and then reacted with labeled antibody, unbound radioactivity being removed by repeated washing. Nonspecific binding with this method was 0.5 to 1% of the total radioactivity added and sensitivities of 0.1 or 10 μg were achieved with 125 I and [ 3 H]acetate, respectively. Immunoglobulins were labeled at the rate of 1 in 300 for 125 I and 1 in 200 with [ 3 H]acetate although there was a 400-fold greater isotopic abundance of 125 I relative to 3 H. The possibility of preparing labeled protein of high specific activity using carrier-free [2- 3 H]iodoacetic acid is discussed.

Iodoacetic acid

10.1128/am.28.1.133-137.1974

Cite

Citations (8)

Sustainable development, climate change and human health in the arctic

International Journal of Circumpolar Health (2010)

Alan J. Parkinson

Presentation and recommendations made to an international experts meeting: "Sustainable Developmentin the Arctic in the Face of Global Climate Change: Scientific, Social, Cultural and EducationalChallenges," Monte Carlo, Monaco, 3–6 March 2009.The statements and positions contained in this report represent the proceedings of the meeting.They are those of the presenter and do not necessarily represent the official position of CDC orthe symposium's sponsors.

Presentation (obstetrics)

Position (finance)

10.3402/ijch.v69i1.17428

Cite

Citations (13)

Invasive pneumococcal disease epidemiology and effectiveness of 23-valent pneumococcal polysaccharide vaccine in Alaska Native adults

Vaccine (2006)

Rosalyn Singleton Jay C. Butler Lisa Bulkow Debby Hurlburt Katherine L. O’Brien

Pneumococcal infections

Pneumococcal polysaccharide vaccine

Pneumococcal vaccine

10.1016/j.vaccine.2006.11.065

Cite

Citations (56)

Increases in Levels of Antibody to Hepatitis B Surface Antigen in an Immunized Population

Clinical Infectious Diseases (1998)

Lisa Bulkow Robert B. Wainwright Lisa Bulkow Robert B. Wainwright Brian J. McMahon

Hepatitis B vaccine is effective in preventing infection with hepatitis B virus (HBV), but its duration of protection is unknown. To examine the effect of exposure to HBV on an immunized population, data were analyzed from a cohort of Alaska Natives who were immunized and then followed up annually for 10 years. A boost in antibody to hepatitis B surface antigen (anti-HBs) was defined as a fourfold rise in levels to ⩾20 mIU/mL that was not accompanied by the presence of antibody to hepatitis B core antigen or attributable to interim vaccination. During 10 years of follow-up, 8.2% of 1,595 vaccinees had boosts in anti-HBs. Persons with boosts did not differ significantly from those without boosts in terms of age, gender, village, initial level of anti-HBs, or level of anti-HBs before the boost. These results underscore the continued exposure to HBV among vaccinees and the continued protection against disease that the vaccine provides.

Hepatitis B

Hepatitis B vaccine

Hepatitis A vaccine

10.1086/513939

Cite

Citations (34)

Evaluation of seaFAST, a Rapid Fluorescent In Situ Hybridization Test, for Detection of Helicobacter pylori and Resistance to Clarithromycin in Paraffin-Embedded Biopsy Sections

Journal of Clinical Microbiology (2005)

Julie Morris Alisa Reasonover Michael G. Bruce Dana L. Bruden Brian J. McMahon

ABSTRACT A commercially available rapid fluorescent in situ hybridization (FISH) test, (seaFAST H. pylori Combi-Kit; SeaPro Theranostics International, Lelystad, The Netherlands) was used to simultaneously detect the presence of Helicobacter pylori and determine clarithromycin susceptibility in paraffin-embedded biopsy sections. The FISH method was found to be 97% sensitive, 94% specific for the detection of H. pylori and comparable to agar dilution for the detection of resistance to clarithromycin.

Agar dilution

10.1128/jcm.43.7.3494-3496.2005

Cite

Citations (40)

International Circumpolar Surveillance (ICS) Summary Report, year 2002 data

Tammy Cottle Michael G. Bruce Alan J. Parkinson

Circumpolar star

Source

Cite

Citations (0)

Detection of virus-specific immunoglobulins using a doubly labeled fluorescein-125I antibody

Journal of Clinical Microbiology (1976)

Alan J. Parkinson J. Kalmakoff

Commercially prepared fluorescein-labeled antihuman antibodies were labed with 125I and used to compre specific herpes simplex virus antibody titers as determined by indirect fluorescent antibody and radioimmunoassay techniques. Total virus-specific immunoglobulin and virus-specific immunoglobulin G titers did not vary by more than one twofold dilution when compared by the two methods.

Antibody titer

10.1128/jcm.3.6.637-639.1976

Cite

Citations (4)

Risk Factors for Nasopharyngeal Carriage of Resistant Streptococcus pneumoniae and Detection of a Multiply Resistant Clone among Children Living in the Yukon-Kuskokwim Delta Region of Alaska

The Pediatric Infectious Disease Journal (1996)

Xilla T. Ussery Bradford D. Gessner Harvey Lipman John A. Elliott Marilyn J. Crain

Background Children <2 years old living in the Yukon-Kuskokwim Delta (YKD) region of Alaska have one of the highest pneumococcal bacteremia rates of in the world. Methods To determine the prevalence of and risk factors for infection with intermediate or resistant Streptococcus pneumoniae in the YKD, we cultured nasopharyngeal secretions of healthy children ≤5 years old, reviewed their hospital records and administered questionnaires to accompanying parents. Results Of 185 children evaluated we obtained 95 pneumococcal isolates; drug susceptibility patterns and serotyping results were available for 92. Of these, 33 (36%) were intermediate or resistant to at least one drug class tested; 27 isolates were intermediate (minimum inhibitory concentration 0.1 to 1.0 mg/l) and none were resistant to penicillin. Compared with other isolates, capsular serotype 6B isolates were more likely to be intermediate or resistant to at least one drug (relative risk, 5.3; P < 0.001) and to more than one drug (relative risk, 17.0; P < 0.001). The majority of 6B isolates had identical pneumococcal surface protein A patterns. Carriage of intermediate or resistant pneumococcus was associated with age <2 years (relative risk, 3.0; P < 0.001) but not with antibiotic use or other evaluated risk factors. Conclusions Young age but not antibiotic use was associated with carriage of intermediate or resistant S. pneumoniae in the YKD region of Alaska. Much of the intermediate or resistant pneumococcus in the YKD may have resulted from the proliferation of a single capsular serotype 6B clone.

Carriage

clone (Java method)

Bacteremia

Pneumococcal infections

10.1097/00006454-199611000-00011

Cite

Citations (42)