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Biomedical subjects

Nancy Cox

Publications and source records attributed to Nancy Cox.

At least 19 recordsLinked to original sources

Inherited Predisposition to Increased Systemic Inflammation Predicts a Broad Class of Disease Phenotypes.

Chronic, low-grade systemic inflammation is a polygenic trait captured with the INFLA-score, a composite of C-reactive protein, platelet count, leukocyte count, and granulocyte-to-lymphocyte ratio. We derived a polygenic risk score from the INFLA-score (iPRS) in a multi-ancestry population from the UK Biobank (n=421,368), then evaluated and used it in a phenome-wide association study among participants in the All of Us Research Program (AoU). The multi-ancestry iPRS was tested for association with the INFLA-score in AoU (N=4,833 with biomarker data) via linear regression, adjusting for age, sex, and genetically-determined principal components (PCs) and with 2,821 phecodeX-defined phenotypes in AoU (N=265,068) via logistic regression, adjusting for sex, age, EHR length, race, ethnicity and PCs. The iPRS predicted the INFLA-score (R-squared=0.026, beta=0.980, p<2x10-16) and was associated with 47 phenotypes (Bonferroni-corrected p<0.05). The strongest associations were with blood-related phenotypes: elevated white blood cell count (OR=1.19, p=3.85x10-66), thrombocytopenia (OR=0.86, p=5.70x10-44), platelet defects (OR=0.86, p=2.47x10-43), neutropenia (OR= 0.86, p=5.52x10-18), myeloproliferative disorder (OR= 1.2, p=2.77x10-15). Others included celiac disease (OR=0.713, p=2.98x10-46), ankylosing spondylitis (OR=1.4, p=1.33 x 10-17), hypertension (OR=1.04, p=4.56x10-15), rheumatoid arthritis (OR=1.09, p=1.02x10-13), hematuria (OR=1.05, p=1.96x10-10). Removing major-histocompatibility-complex SNPs abolished associations with known autoimmune diseases, while all other associations remained. We replicated 17 (42.5%) of 40 significant phenotypes available in the Vanderbilt University Medical Center's BioVU. Our findings demonstrate that systemic inflammation can be predicted using the iPRS across multiple ancestries, and the iPRS is associated with numerous clinical endpoints. This multi-ancestry iPRS may have future utility in stratifying risk for inflammation-driven conditions across diverse populations.

Journal Article↗

Are genome-wide association studies all that we need to dissect the genetic component of complex human diseases?

With the availability of dense maps of anonymous and frequent SNPs spanning the whole human genome, genome-wide association studies are now becoming a reality. In this paper, we discuss the utility of these approaches to detect genetic risk variants involved in complex disease susceptibility and, in the best case scenario where a signal is detected, how helpful it will be to the understanding of the pathological process.

Genetic Diseases, Inborn↗

Three Indonesian clusters of H5N1 virus infection in 2005.

BACKGROUND: Since 2003, the widespread ongoing epizootic of avian influenza A (H5N1) among poultry and birds has resulted in human H5N1 cases in 10 countries. The first case of H5N1 virus infection in Indonesia was identified in July 2005. METHODS: We investigated three clusters of Indonesian cases with at least two ill persons hospitalized with laboratory evidence of H5N1 virus infection from June through October 2005. Epidemiologic, clinical, and virologic data on these patients were collected and analyzed. RESULTS: Severe disease occurred among all three clusters, including deaths in two clusters. Mild illness in children was documented in two clusters. The median age of the eight patients was 8.5 years (range, 1 to 38). Four patients required mechanical ventilation, and four of the eight patients (50%) died. In each cluster, patients with H5N1 virus infection were members of the same family, and most lived in the same home. In two clusters, the source of H5N1 virus infection in the index patient was not determined. Virus isolates were available for one patient in each of two clusters, and molecular sequence analyses determined that the isolates were clade 2 H5N1 viruses of avian origin. CONCLUSIONS: In 2005 in Indonesia, clusters of human infection with clade 2 H5N1 viruses included mild, severe, and fatal cases among family members.

Adult↗

Immunogenicity and reactogenicity of 1 versus 2 doses of trivalent inactivated influenza vaccine in vaccine-naive 5-8-year-old children.

BACKGROUND: Two doses of trivalent inactivated influenza vaccine (TIV) are recommended for children <9 years old receiving vaccine for the first time, but compliance is suboptimal. This study assessed the need for a second dose of TIV in this age group. METHODS: In this prospective, open-label study, 232 influenza vaccine-naive 5-8-year-olds enrolled in a health maintenance organization received 2 doses of TIV in fall 2004. Serum for antibody titer measurement was obtained at 3 time points (n = 222). Parents completed diaries for 5 days. RESULTS: Both doses of vaccine were well tolerated. The strongest predictor of a protective antibody response (> or =1 : 40) after 1 dose of TIV was baseline seropositive status. In multivariate analysis adjusting for age, sex, and baseline serostatus, the proportion of children with protective antibody responses was significantly higher after 2 doses than after 1 dose of TIV for each antigen (P < .001, for A/H1N1; P = .01, for A/H3N2; P < .001, for B). Age and sex were not independently predictive of a protective antibody response. Over one-third of children had antibody responses <1:40 for the type B vaccine component, even after 2 doses. CONCLUSIONS: The present study supports the need for 2 doses of TIV in 5-8-year-olds receiving TIV for the first time. Efforts to increase compliance with the 2-dose recommendation are warranted.

Antibodies, Viral↗

Identification of a functional polymorphism of the human type 5 17beta-hydroxysteroid dehydrogenase gene associated with polycystic ovary syndrome.

CONTEXT: Polycystic ovary syndrome (PCOS) is characterized by chronic hyperandrogenic anovulation and is associated with insulin resistance. Its pathogenesis is believed to be multifactorial, and abnormal gene regulation could be one contributing factor. Type 5 17beta-hydroxysteroid dehydrogenase (17beta-HSD5) appears to be the major testosterone-forming 17beta-HSD isoenzyme in females. OBJECTIVE: Our objective was to investigate the role of a potentially activating 17beta-HSD5 gene (HSD17B5) variant in hyperandrogenism. DESIGN AND SETTING: We conducted a case study and case-control cohort study in our General Clinical Research Center. STUDY SUBJECTS: Subjects included a case of PCOS who had hyperthecosis associated with profound type B insulin resistance and an unusual, frankly male testosterone response to a GnRH agonist test, as well as 121 PCOS patients and 128 population controls. INTERVENTIONS: Interventions were diagnostic. MAIN OUTCOME MEASURES: Main outcome measures included sequencing of HSD17B5 5'-flanking region and nine exons, genotype/phenotype studies, and in vitro functional studies. RESULTS: Our case had a previously undescribed homozygous HSD17B5 variant (G-to-A substitution) -71 bp in the promoter region. Genotyping controls showed this to be a single-nucleotide polymorphism (SNP)-71G. Luciferase activity of a SNP-71G promoter construct was significantly higher than that of the wild type, and EMSAs revealed that SNP-71G possessed significantly increased affinity to nuclear transcription factors. SNP-71G allele frequency (32.2 vs. 22.3%) and SNP-71G allele presence (53.7% vs. 38.3%) were significantly increased in PCOS (P = 0.01) [corrected] SNP-71G homozygosity tended to contribute about 20% to the plasma testosterone level. CONCLUSIONS: SNP-71G is a functional polymorphism that may contribute to testosterone excess in a subset of PCOS patients.

17-Hydroxysteroid Dehydrogenases↗

Genetic epidemiology of diabetes.

Conventional genetic analysis focuses on the genes that account for specific phenotypes, while traditional epidemiology is more concerned with the environmental causes and risk factors related to traits. Genetic epidemiology is an alliance of the 2 fields that focuses on both genetics, including allelic variants in different populations, and environment, in order to explain exactly how genes convey effects in different environmental contexts and to arrive at a more complete comprehension of the etiology of complex traits. In this review, we discuss the epidemiology of diabetes and the current understanding of the genetic bases of obesity and diabetes and provide suggestions for accelerated accumulation of clinically useful genetic information.

Diabetes Mellitus↗

Daisy Ayris Lecture. The operating room: a personal history.

This is the first of two articles based on a presentation given at NATN Congress 2004. The presentation was given as the Daisy Ayris Memorial Lecture. In this article NATN archivist Nancy Cox describes her experiences working in the operating room beginning in the 1950s.

History, 20th Century↗

Daisy Ayris Lecture. The history of NATN. 40 years and counting.

Nancy Cox joined NATN in 1970, becoming deputy secretary in 1972, and national secretary from 1985-1989. This article is the second part of the Daisy Ayris Memorial Lecture given at Congress 2004. Nancy gives us a fascinating insight into the early days of the organisation, and how it has become the association it is today.

Forecasting↗

Emergence and transmission of amantadine-resistant influenza A in a nursing home.

OBJECTIVES: To prospectively detect amantadine-resistant influenza when amantadine was used for influenza A outbreak control. DESIGN: Prospective clinical surveillance and viral culture of all new respiratory illnesses during the course of amantadine prophylaxis. SETTING: A 721-bed, 14-ward nursing home for veterans and spouses during an influenza A outbreak (1993-94). PARTICIPANTS: Residents of a veterans hospital and their spouses. MEASUREMENTS: Nasopharyngeal and throat viral culture. All residents with positive cultures who developed new respiratory symptoms while receiving or residing on a unit receiving amantadine prophylaxis had antiviral-resistance testing and polymerase chain reaction restriction analyses performed. RESULTS: Amantadine prophylaxis was administered sequentially on nine of 14 wards to all well residents for 14 to 31 days/ward to control influenza outbreaks between December 9, 1993, and January 28, 1994. Amantadine treatment was simultaneously provided to 29 ill residents. Between December 3, 1993, and January 22, 1994, 68 culture-positive cases of influenza A were detected. Twenty subjects were receiving or residing on units receiving amantadine prophylaxis. Amantadine sensitivity testing could be performed on 16 residents; 12 residents had amantadine resistant strains. Four of the 12 had not received any antiviral treatment. Illness onset ranged from 1 to 22 days after amantadine prophylaxis was begun on the individual's unit. Two ribonucleic acid (RNA) mutations in the gene coding the M2 protein transmembrane region were observed that were clustered in time and space. Isolates from two roommates, one receiving amantadine for 18 days and one on no antiviral, had identical RNA sequences. CONCLUSION: Antiviral resistance may be responsible for failure of prophylaxis in nursing home outbreaks. Strategies that use different classes of antivirals for prophylaxis and treatment may limit emergence and transmission of resistant virus.

Amantadine↗

Generation and evaluation of a high-growth reassortant H9N2 influenza A virus as a pandemic vaccine candidate.

H9N2 subtype avian influenza viruses (AIVs) are widely distributed in avian species and were isolated from humans in Hong Kong and Guangdong province, China in 1999 raising concern of their potential for pandemic spread. We generated a high-growth reassortant virus (G9/PR8) that contains the hemagglutinin (HA) and neuraminidase (NA) genes from the H9N2 avian influenza virus A/chicken/Hong Kong/G9/97 (G9) and six internal genes from A/Puerto Rico/8/34 (PR8) by genetic reassortment, for evaluation as a potential vaccine candidate in humans. Pathogenicity studies showed that the G9/PR8 reassortant was not highly pathogenic for mice or chickens. Two doses of a formalin-inactivated G9/PR8 virus vaccine induced hemagglutination inhibiting antibodies and conferred complete protection against challenge with G9 and the antigenically distinct H9N2 A/Hong Kong/1073/99 (G1-like) virus in a mouse model. These results indicate that the high growth G9/PR8 reassortant has properties that are desirable in a vaccine seed virus and is suitable for evaluation in humans for use in the event of an H9 pandemic.

Animals↗

A novel coronavirus associated with severe acute respiratory syndrome.

BACKGROUND: A worldwide outbreak of severe acute respiratory syndrome (SARS) has been associated with exposures originating from a single ill health care worker from Guangdong Province, China. We conducted studies to identify the etiologic agent of this outbreak. METHODS: We received clinical specimens from patients in seven countries and tested them, using virus-isolation techniques, electron-microscopical and histologic studies, and molecular and serologic assays, in an attempt to identify a wide range of potential pathogens. RESULTS: None of the previously described respiratory pathogens were consistently identified. However, a novel coronavirus was isolated from patients who met the case definition of SARS. Cytopathological features were noted in Vero E6 cells inoculated with a throat-swab specimen. Electron-microscopical examination revealed ultrastructural features characteristic of coronaviruses. Immunohistochemical and immunofluorescence staining revealed reactivity with group I coronavirus polyclonal antibodies. Consensus coronavirus primers designed to amplify a fragment of the polymerase gene by reverse transcription-polymerase chain reaction (RT-PCR) were used to obtain a sequence that clearly identified the isolate as a unique coronavirus only distantly related to previously sequenced coronaviruses. With specific diagnostic RT-PCR primers we identified several identical nucleotide sequences in 12 patients from several locations, a finding consistent with a point-source outbreak. Indirect fluorescence antibody tests and enzyme-linked immunosorbent assays made with the new isolate have been used to demonstrate a virus-specific serologic response. This virus may never before have circulated in the U.S. population. CONCLUSIONS: A novel coronavirus is associated with this outbreak, and the evidence indicates that this virus has an etiologic role in SARS. Because of the death of Dr. Carlo Urbani, we propose that our first isolate be named the Urbani strain of SARS-associated coronavirus.

Adult↗

Mortality associated with influenza and respiratory syncytial virus in the United States.

CONTEXT: Influenza and respiratory syncytial virus (RSV) cause substantial morbidity and mortality. Statistical methods used to estimate deaths in the United States attributable to influenza have not accounted for RSV circulation. OBJECTIVE: To develop a statistical model using national mortality and viral surveillance data to estimate annual influenza- and RSV-associated deaths in the United States, by age group, virus, and influenza type and subtype. DESIGN, SETTING, AND POPULATION: Age-specific Poisson regression models using national viral surveillance data for the 1976-1977 through 1998-1999 seasons were used to estimate influenza-associated deaths. Influenza- and RSV-associated deaths were simultaneously estimated for the 1990-1991 through 1998-1999 seasons. MAIN OUTCOME MEASURES: Attributable deaths for 3 categories: underlying pneumonia and influenza, underlying respiratory and circulatory, and all causes. RESULTS: Annual estimates of influenza-associated deaths increased significantly between the 1976-1977 and 1998-1999 seasons for all 3 death categories (P<.001 for each category). For the 1990-1991 through 1998-1999 seasons, the greatest mean numbers of deaths were associated with influenza A(H3N2) viruses, followed by RSV, influenza B, and influenza A(H1N1). Influenza viruses and RSV, respectively, were associated with annual means (SD) of 8097 (3084) and 2707 (196) underlying pneumonia and influenza deaths, 36 155 (11 055) and 11 321 (668) underlying respiratory and circulatory deaths, and 51 203 (15 081) and 17 358 (1086) all-cause deaths. For underlying respiratory and circulatory deaths, 90% of influenza- and 78% of RSV-associated deaths occurred among persons aged 65 years or older. Influenza was associated with more deaths than RSV in all age groups except for children younger than 1 year. On average, influenza was associated with 3 times as many deaths as RSV. CONCLUSIONS: Mortality associated with both influenza and RSV circulation disproportionately affects elderly persons. Influenza deaths have increased substantially in the last 2 decades, in part because of aging of the population, underscoring the need for better prevention measures, including more effective vaccines and vaccination programs for elderly persons.

Adolescent↗

Evaluation of a genetically modified reassortant H5N1 influenza A virus vaccine candidate generated by plasmid-based reverse genetics.

Avian influenza A H5N1 viruses similar to those that infected humans in Hong Kong in 1997 continue to circulate in waterfowl and have reemerged in poultry in the region, raising concerns that these viruses could reappear in humans. The currently licensed trivalent inactivated influenza vaccines contain hemagglutinin (HA) and neuraminidase genes from epidemic strains in a background of internal genes derived from the vaccine donor strain, A/Puerto Rico/8/34 (PR8). Such reassortant candidate vaccine viruses are currently not licensed for the prevention of human infections by H5N1 influenza viruses. A transfectant H5N1/PR8 virus was generated by plasmid-based reverse genetics. The removal of the multibasic amino acid motif in the HA gene associated with high pathogenicity in chickens, and the new genotype of the H5N1/PR8 transfectant virus, attenuated the virus for chickens and mice without altering the antigenicity of the HA. A Formalin-inactivated vaccine prepared from this virus was immunogenic and protected mice from subsequent wild-type H5N1 virus challenge. This is the first successful attempt to develop an H5N1 vaccine seed virus resembling those used in currently licensed influenza A vaccines with properties that make it a promising candidate for further evaluation in humans.

Animals↗

Methods for analysis and visualization of SNP genotype data for complex diseases.

SNP markers are becoming central for studying genetic determinants of complex diseases. Large SNP data collected in such studies call for the development of specialized analysis tools. We present methods for selecting sets of SNPs that can be associated to sample properties in case/control studies. We also describe how scoring and selection can be statistically tested. This is done at the single locus as well as at the set level.

Bayes Theorem↗

The total influenza vaccine failure of 1947 revisited: major intrasubtypic antigenic change can explain failure of vaccine in a post-World War II epidemic.

Although vaccine-induced immunity to influenza A virus is continually challenged by progressively selected mutations in the virus's major antigens (antigenic drift), virus strains within a subtype (e.g., H1N1) are antigenically cross-reactive. Although cross-immunity diminishes as further mutations accumulate, necessitating frequent changes in vaccine strains, older vaccines are usually partially protective. The post-World War II epidemic of 1947 is notable for the total failure of a vaccine previously effective in the 1943-44 and 1944-45 seasons. We have combined extensive antigenic characterization of the hemagglutinin and neuraminidase antigens of the 1943 and 1947 viruses with analysis of their nucleotide and amino acid sequences and have found marked antigenic and amino acid differences in viruses of the two years. Furthermore, in a mouse model, vaccination with the 1943 vaccine had no effect on infection with the 1947 strain. These findings are important, because complete lack of cross-immunogenicity has been found previously only with antigenic shift, in which antigenically novel antigens have been captured by reassortment of human and animal strains, sometimes leading to pandemics. Although the 1947 epidemic lacked the usual hallmarks of pandemic disease, including an extensive increase in mortality, it warns of the possibility that extreme intrasubtypic antigenic variation (if coupled with an increase in disease severity) could produce pandemic disease without the introduction of animal virus antigens.

Animals↗

Preparing for pandemic influenza: the need for enhanced surveillance.

In the US, planning for the next influenza pandemic is occurring in parallel at the national, state and local levels. Certain issues, such as conducting surveillance and purchasing pandemic vaccine, require co-ordination at the national level. However, most prevention and control actions will be implemented at the state and local levels, which vary widely in terms of population demographics, culture (e.g. rural versus urban) and available resources. In 1995, a survey by the Council of State and Territorial Epidemiologists (CSTE) found that only 29 (59%) states perceived a need to develop a specific influenza pandemic plan for their jurisdiction. Since then, the process of developing state and local plans has gained considerable momentum. Integration of these efforts with the national planning process has been facilitated by: (1) the mutual involvement of state and federal staff in both processes; (2) the sharing of draft documents; (3) the ongoing occurrence of local and national co-ordinating meetings; (4) the provision of financial resources by the federal government. So far, approximately 12 states either have drafted or begun drafting a state and local influenza pandemic plan. One of the benefits of the collaborative planning process has been the development of new working relationships and partnerships among several agencies at the state, local and national levels. Such efforts will improve our collective ability to rapidly investigate and control other emerging or re-emerging public health threats in the 21st century, be it a bioterrorist event, pandemic influenza, or any other catastrophic health event.

Animals↗