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Biomedical subjects

W H Wolfe

Publications and source records attributed to W H Wolfe.

16 recordsLinked to original sources

Paternal serum dioxin and reproductive outcomes among veterans of Operation Ranch Hand.

We studied whether paternal exposure to Agent Orange and its dioxin contaminant (2,3,7,8-tetrachlorodibenzo-p-dioxin) during the Vietnam War is related to adverse reproductive outcomes after service in Southeast Asia. The index cohort comprises conceptions and children of veterans of Operation Ranch Hand, the unit responsible for aerial spraying of herbicides in Vietnam from 1962 to 1971. The comparison cohort comprises conceptions and children of Air Force veterans who served in Southeast Asia during the same period but who were not involved with spraying herbicides. We found no meaningful elevation in risk for spontaneous abortion or stillbirth. In analyses of birth defects, we found elevations in risk in some organ system categories, which, after review of the clinical descriptions, were found to be not biologically meaningful. There was an increase in nervous system defects in Ranch Hand children with increased paternal dioxin, but it was based on sparse data. We found no indication of increased birth defect severity, delays in development, or hyperkinetic syndrome with paternal dioxin. These data provide little or no support for the theory that paternal exposure to Agent Orange and its dioxin contaminant is associated with adverse reproductive outcomes.

2,4,5-Trichlorophenoxyacetic Acid

Determinants of TCDD half-life in veterans of operation ranch hand.

The half-life of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) changed significantly with body fat and age in 337 members of Operation Ranch Hand, the Air Force unit responsible for the aerial spraying of Agent Orange in Vietnam. Using paired TCDD measurements derived from serum collected in 1982 and in 1987, we investigated how TCDD half-life varied with percent body fat (PBF), relative changes in PBF, and age. We found that half-life increased significantly with increasing PBF and decreased significantly with increasing relative change in PBF and with age. The median observed half-life of TCDD for these 337 veterans is 11.3 yr with a nonparametric 95% confidence interval of 10.0-14.1 yr.

Adipose Tissue

Duration of antibody response after meningococcal polysaccharide vaccination in US Air Force personnel.

The long-term kinetics of the immunologic response after vaccination of adults with Neisseria meningitidis polysaccharide vaccine is unknown. Total meningococcal anti-capsular antibody response (measured by ELISA) and serum bactericidal activity after routine vaccination with quadrivalent meningococcal vaccine were evaluated in US Air Force personnel. In a retrospective cross-sectional study, blood samples were obtained from approximately 40 personnel before vaccination, at 1 and 4-6 months, and at 2, 3, 4, 6, 8, and 10 years after vaccination. Total anti-group A and -group C capsular antibody levels and bactericidal activity peaked 1 month after vaccination and declined substantially by 2 years. At each interval, significantly higher levels of total antibody and bactericidal activity were detected than before vaccination. Anti-capsular antibodies and bactericidal activity persisted for up to 10 years after immunization. These and further studies on the serologic measure of protection against meningococcal disease are important for evaluation of candidate vaccines and development of recommendations for immunization.

Adult

Viral hepatitis in the U.S. Air Force, 1980-89: an epidemiological and serological study.

This paper reports the epidemiology of hospital-diagnosed acute viral hepatitis in U.S. Air Force personnel from 1980-89. First hospitalizations for viral hepatitis generally declined, ranging from 24.6 to 47.2 per 100,000 personnel. Hepatitis rates were higher among men, (RR = 1.3; 95% C.I., 1.1-1.5) and higher among blacks, compared to whites (RR = 1.4; 95% C.I., 1.3-1.6). Analysis of risk associated with various occupations demonstrated an increased risk of viral hepatitis for procedurally oriented medical personnel (physicians, clinical nurses, dentists) when compared to all other occupations (RR = 1.5; 95% C.I., 1.1-1.9). Pilots and navigators demonstrated a decreased risk of acute viral hepatitis. Members hospitalized for hepatitis B had a prior or concurrent diagnosis for sexually transmitted disease in 37% of cases; for drug abuse, 32% of cases. Serum samples from 332 individuals demonstrated that hepatitis A had the highest rate of agreement (84%) between serology and hospital discharge diagnosis. Only 3% of individuals with the diagnosis of NANB hepatitis were positive for hepatitis C.

Adolescent

Viral hepatitis in the US Air Force, 1980-1989.

Viral hepatitis and its acute and chronic complications continue to pose significant threats to the readiness of military personnel. Knowledge about the specific viral agents and their routes of transmission are important in developing prevention strategies. A recent analysis of hepatitis in the US Navy for the period 1975-1984 is reviewed. In order to better characterize the risk of viral hepatitis among US Air Force personnel, a comprehensive review of inpatient and quarters data for hepatitis A, B and 'non-A, non-B' were reviewed from Air Force medical treatment facilities worldwide for the period 1980-1989. Following a discussion of the study methodology, preliminary data and hepatitis type-specific demographic risk variables are discussed. Preliminary results from a hepatitis serosurvey (A, B and C antibody with use of a supplemental validating assay) of the subset of the study cohort who are currently on active duty are briefly reviewed.

Aerospace Medicine

Immunological parameters in current and former US Air Force personnel.

As part of a comprehensive study of current and former US Air Force personnel, an extensive assessment of the immune system of 497 normal male subjects was conducted in 1987. Cell surface marker studies for CD2 (total T cells), CD4 (helper T cells), CD8 (suppressor T cells), CD25 (activated T cells), CD20 (total B cells), CD14 (monocytes), and HLA-DR positive cell populations were measured. The CD4/CD8 ratio was also calculated. Functional stimulation assays were also performed using phytohemagglutinin (PHA) and a culture of mixed lymphocytes. Assays of natural killer cells with and without interleukin-2 stimulation were done. In addition to the distribution and range of values for each assay, statistical analyses were performed to determine the effect of age, race, percentage body fat, tobacco use and alcohol consumption on each variable. Age and alcohol consumption had significant correlation with suppressed counts and functions on nearly all variables while tobacco use was associated with stimulation of both T-cell numbers and function. These findings highlight the importance of using age-specific ranges of normal values for these tests of immunity and the need to consider life-style factors in the interpretation of the laboratory assessment of immune status.

Aerospace Medicine

Health status of Air Force veterans occupationally exposed to herbicides in Vietnam. I. Physical health.

The Air Force Health Study is a 20-year comprehensive assessment of the health of Air Force veterans of Operation Ranch Hand, the unit responsible for aerial spraying of herbicides in Vietnam. The study compares the health and noncombat mortality of Ranch Hand veterans with a comparison group of Air Force veterans primarily involved with cargo missions in Southeast Asia but who were not exposed to herbicides. This report summarizes the health of these veterans as determined at the third in a series of physical examinations. Nine hundred ninety-five Ranch Hands and 1299 comparison subjects attended the second follow-up examination in 1987. The two groups were similar in reported health problems, diagnosed skin conditions, and hepatic, cardiovascular, and immune profiles. Ranch Hands have experienced significantly more basal cell carcinomas than comparison subjects. The two groups were not different with respect to melanoma and systemic cancer.

2,4,5-Trichlorophenoxyacetic Acid

Health status of Air Force veterans occupationally exposed to herbicides in Vietnam. II. Mortality.

The Air Force Health Study is a 20-year comprehensive assessment of the current health of Air Force veterans of Operation Ranch Hand, the unit responsible for aerial spraying of herbicides in Vietnam. This report compares the noncombat mortality of 1261 Ranch Hand veterans to that of a comparison population of 19,101 other Air Force veterans primarily involved in cargo missions in Southeast Asia but who were not exposed to herbicides. The indirectly standardized all-cause death rate among Ranch Hands is 2.5 deaths per 1000 person-years, the same as that among comparison subjects. After adjustment for age, rank, and occupation, the all-cause standardized mortality ratio was 1.0. In adjusted cause-specific analyses, we found no significant group differences regarding accidental, malignant neoplasm, and circulatory deaths. These data are not supportive of a hypothesis of increased mortality among Ranch Hands.

Accidents

Estimates of the half-life of 2,3,7,8-tetrachlorodibenzo-p-dioxin in Vietnam Veterans of Operation Ranch Hand.

The half-life of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD; commonly known as dioxin) in serum has been measured in 36 Air Force Vietnam veterans of Operation Ranch Hand, which was the operation that aerially sprayed the herbicide Agent Orange in Vietnam. From serum specimens taken in 1982 and 1987, the median half-life of 2,3,7,8-TCDD in these Ranch Hand veterans was found to be 7.1 yr (95% confidence interval about the median of 5.8-9.6 yr). These veterans reported no civilian exposure to dioxin or herbicides. Concentrations of 2,3,7,8-TCDD in the 1982 serum specimens from these veterans ranged from 16.9 to 423 parts per trillion on a lipid weight basis. The half-life estimates were not associated with the concentration of 2,3,7,8-TCDD in the 1982 serum specimens. This half-life of 7.1 yr is much longer than the half-life of 2,3,7,8-TCDD reported in animals but is consistent with recent evidence from other human exposures to 2,3,7,8-TCDD.

Adult

An outbreak of gastroenteritis due to a heat-labile enterotoxin-producing strain of Escherichia coli.

In April 1981, an outbreak of gastroenteritis, characterized by diarrhea and abdominal cramps, occurred in 282 of approximately 3,000 personnel at a large metropolitan hospital in San Antonio, Tex. There was a significant association between illness and eating at the hospital cafeteria (P = 0.0008), but no specific food could be incriminated. Stools or rectal swabs from 54 ill individuals produced almost pure cultures of Escherichia coli. Cultures from 51 of these subjects had identical antibiotic sensitivity patterns, and 38 had the same biotype. Isolates from 45 persons were tested for production of heat-stable and heat-labile enterotoxins, using the suckling mouse and Y-1 adrenal cell assays, respectively. Of 45 isolates, 41 produced heat-labile enterotoxins, while 0 of 45 produced heat-stabile enterotoxins. Two isolates were rough, and 34 of the remaining 43 were serotype O25:H-. Two strains were O25:H+. None of the 45 strains possessed hemagglutination patterns typical of colonization factor antigens I or II. Six of seven O25:H- heat-labile enterotoxin-positive strains selected at random were piliated as seen by electron microscopy but did not agglutinate with anti-colonization factor antigens I or II antisera.

Diarrhea

Indices of TCDD exposure and TCDD body burden in veterans of Operation Ranch Hand.

Using responses from a questionnaire detailing herbicide exposure during service in Vietnam and information on job classifications, we investigated the relationship between 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) body burden and self-reported exposure in enlisted members of Operation Ranch Hand, the United States Air Force herbicide spraying mission in Vietnam. We constructed three TCDD exposure indices from the questionnaire data: the number of days of skin exposure (DAYS), the percentage of skin area exposed (PCNT), and a combined index (SRI) which was the product of these and the concentration of TCDD in the herbicide. A fourth index (AFI) based on gallons of herbicide sprayed and the number of men on the job was also studied. The regression model most predictive of TCDD levels (R2 = 0.61) included job classification (divided into four categories), the number of days of skin exposure, percent body fat during the tour of duty, and relative change in body fat. A model with job classification alone had an R2 of 0.60. The four exposure indices were constructed to further explain TCDD exposure in the job classifications with the highest potential for exposure: Ranch Hand flight engineers and ground crew. In these two groups, days of skin exposure was the index most significantly associated with TCDD levels. Overall, the best index of exposure was the number of days of skin exposure to herbicide.

Adipose Tissue

Alcohol-related mortality in the U.S. Air Force, 1990.

Alcohol-related morbidity and mortality represent a major public health problem in the United States, particularly among young men. Standardized comparisons of alcohol use have demonstrated that members of the military consume more alcohol than matched civilians. To quantify the impact of alcohol use by active duty members of the Air Force for calendar year 1990, we reviewed 283 death certificates and analyzed the cause of death using the Alcohol-Related Disease Impact (ARDI) computer program. Injuries accounted for 73% of all deaths among active duty Air Force personnel, with motor vehicle accidents (MVAs) accounting for 31% of total mortality. Sixty-six deaths (23%) were attributable to alcohol-related causes and accounted for 2,300 years of potential life lost before 65 years of age. Analysis of blood alcohol levels taken from a subset of active duty deaths resulting from MVAs and suicides yielded alcohol-attributable fractions similar to those obtained by the ARDI method. Periodic assessment and dissemination of alcohol-related mortality statistics in the military using the ARDI methodology represent an important public health education tool.

Accidents, Traffic