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Biomedical subjects

Gary D Gackstetter

Publications and source records attributed to Gary D Gackstetter.

7 recordsLinked to original sources
PubMed2003

Molecular genetic analysis of 675 group A streptococcus isolates collected in a carrier study at Lackland Air Force Base, San Antonio, Texas.

Contemporary molecular genetic analysis methods have not been used to study large samples of carriage isolates of group A Streptococcus. To determine the emm types causing asymptomatic carriage and pharyngitis in a closed population, we analyzed 675 isolates recovered from a population-based surveillance study of 10,634 recruits at Lackland Air Force Base, Texas, during 4 months in 1993-1994. Strains with emm1 and emm6 alleles accounted for only 22% of the isolates recovered from asymptomatic recruits at entrance to training. However, these 2 emm types caused 69% of the pharyngitis cases identified during training and represented 51% of the isolates recovered from the throat on exit from training. Sequence analysis of the hypervariable sic gene documented that distinct emm1 subclones disseminated in specific training groups called flights. The preferential increase in the prevalence of emm1 and emm6 isolates during the 6-week training period indicates an enhanced ability of these strains to disseminate and cause disease in this population.

Alleles↗
PubMed2003

Identifying new diseases and their causes: the dilemma of illnesses in Gulf War veterans.

Since the Gulf War, investigation continues of symptoms and illnesses among its veterans. Yet, identifying a specific "Gulf War Syndrome" remains elusive. With new disease entities, causal associations are relatively easily established when the condition is serious, verifiable, and has excess disease rates in specific groups. In common conditions, many excess cases are required to establish association with a specific exposure. Establishing causality in syndromes with variable symptoms is difficult because specific diagnostic algorithms must be established before causal factors can be properly investigated. Searching for an environmental cause is futile in the absence of an operational disease case definition. Common subjective symptoms (without objective physical or laboratory findings) account for over one-half of all medical outpatient visits, yet these symptoms lack an identified physical cause at least one-third of the time. Our medical care system has difficulty dealing with disorders where there is no identified anatomic abnormality or documented metabolic/physiological dysfunction.

Causality↗
PubMed2002

Are Gulf War veterans experiencing illness due to exposure to smoke from Kuwaiti oil well fires? Examination of Department of Defense hospitalization data.

There has been much concern among the public and veterans that specific environmental exposures incurred during the Gulf War were the cause of subsequent illness among Gulf War veterans. In this historical cohort study, the authors compared the postwar morbidity of US military personnel exposed to smoke from the 1991 Kuwaiti oil well fires with that of unexposed personnel. Complete exposure and demographic data were available for 405,142 active-duty Gulf War veterans who did not remain in the region after the war. The authors used data from all Department of Defense hospitals for the period August 1, 1991-July 31, 1999 to estimate rates of hospitalization due to any cause, hospitalization due to a diagnosis in one of 15 major categories, and hospitalization due to one of nine diagnoses likely to be manifestations of smoke exposure. Exposures to particulate matter from oil-well-fire smoke were based on the integration of meteorologic data, diffusion modeling, and troop location data. The authors constructed seven exposure groups combining duration and amount of exposure. In Cox modeling, three of the 25 models showed an increased adjusted risk of hospitalization. However, there was no evidence of a dose-response relation. Despite some limitations, these data do not support the hypothesis that Gulf War veterans have an increased risk of postwar morbidity from exposure to Kuwaiti oil-well-fire smoke.

Adolescent↗
PubMed2002

Foodborne illness: new developments concerning an old problem.

Foodborne illnesses continue to cause substantial morbidity and mortality in the United States, primarily as gastroenteritis but occasionally as other syndromes as well. Most of these illnesses are caused by a variety of widely known infectious agents, principally viruses, and are probably the result of common mistakes in food handling in the home or in restaurants. The epidemiology of foodborne illness is evolving. Major changes in food production, distribution, and consumption have created opportunities for new pathogens to emerge and for old ones to reemerge, and the potential for widespread outbreaks is increasing. Antibiotic resistance in bacterial pathogens resulting from the widespread use of antimicrobial agents in animal husbandry is also an important concern. Clinicians must be aware of the changing epidemiology of foodborne illness to recognize and manage these conditions in the clinical setting. In addition, clinicians are critical in the reporting of recognized or suspected foodborne illness, so that public health authorities are able to investigate, understand, and ultimately better control them. A number of new techniques have been employed, and others under development will improve our ability to recognize and cope with foodborne diseases.

Bacterial Infections↗
PubMed2002

Ten years and 100,000 participants later: occupational and other factors influencing participation in US Gulf War health registries.

For more than a decade after the Gulf War, there has been concern that wartime exposures have resulted in significant morbidity among Gulf War veterans. After the end of the war, the Department of Veterans Affairs (VA) and the Department of Defense (DoD) initiated health registries to provide systematic clinical evaluations of Gulf War veterans who chose to participate. By September 1999, there were 32,876 participants in the DoD Comprehensive Clinical Evaluation Program and 70,385 participants in the VA Gulf War Registry Health Examination Program. We identified demographic and military service factors, as well as potential war-related exposures associated with subsequent registry participation after 10 years of observation. Veterans potentially exposed to oil well fire smoke, those near Khamisiyah, Reserve and National Guard, Army veterans, and veterans in the theater of operations during intense combat periods were most likely to elect to participate in a registry. These findings support the hypothesis that certain occupational factors and wartime exposures may influence subsequent health care-seeking behavior.

Adult↗
PubMed2002

The millennium Cohort Study: a 21-year prospective cohort study of 140,000 military personnel.

Does military service, in particular operational deployment, result in a higher risk of chronic illness among military personnel and veterans? The Millennium Cohort Study, the largest Department of Defense prospective cohort study ever conducted, will attempt to answer this question. The probability-based sample of 140,000 military personnel will be surveyed every 3 years during a 21-year period. The first questionnaire, scheduled for release in summer 2001, will be sent to 30,000 veterans who have been deployed to southwest Asia, Bosnia, or Kosovo since August 1997 and 70,000 veterans who have not been deployed to these conflict areas. Twenty thousand new participants will be added to the group in each of the years 2004 and 2007 to complete the study population of 140,000. The participants will have the option of completing the study questionnaire either on the paper copy received in the mail or through the World Wide Web-based version, which is available at www.MillenniumCohort.org. This will be one of the first prospective studies ever to offer such an option. The initial survey instrument will collect data regarding demographic characteristics, self-reported medical conditions and symptoms, and health-related behaviors. Validated instruments will be incorporated to capture self-assessed physical and mental functional status (Short Form for Veterans), psychosocial assessment (Patient Health Questionnaire), and post-traumatic stress disorder (Patient Checklist-17). Information obtained from the survey responses will be linked with other military databases, including data on deployment, occupation, vaccinations, health care utilization, and disability. In addition to revealing changes in veterans' health status over time, the Millennium Cohort Study will serve as a data repository, providing a solid foundation upon which additional epidemiological studies may be constructed.

Chronic Disease↗