Serum dioxin, chloracne, and acne in veterans of Operation Ranch Hand.

The possible relationship between exposure to Agent Orange and its contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin), during the Vietnam War and chloracne was investigated. The index subjects were veterans of Operation Ranch Hand, the unit responsible for aerial herbicide spraying in Vietnam from 1962 to 1971. Other Air Force veterans who served in Southeast Asia during the same period, but who were not involved with spraying herbicides, served as comparisons. None of the Ranch Hand veterans were diagnosed with chloracne; therefore, we restricted our analyses to acne. We found no meaningful or consistent association between dioxin exposure and prevalence of acne without or with regard to anatomical location. These results suggested that exposure of Ranch Hand veterans to dioxin was insufficient for the production of chloracne or perhaps the exposure may have caused chloracne that resolved and was currently undetectable.

Paternal dioxin, preterm birth, intrauterine growth retardation, and infant death.

We studied paternal exposure to Agent Orange and its dioxin contaminant (2,3,7,8-tetrachlorodibenzo-p-dioxin) and preterm birth, intrauterine growth retardation, or infant death in veterans of Operation Ranch Hand, the unit responsible for spraying herbicides during the Vietnam war. A Comparison group of Air Force veterans who served in Southeast Asia during the same time period and who were not occupationally exposed to herbicides was included. We studied children conceived during or after the father's service in Southeast Asia and based exposure on paternal dioxin measured in 1987 or 1992 extrapolated to the time of conception of the child. We assigned each child to one of four exposure categories: Comparison and three Ranch Hand categories (Background, Low, High). Children in the High (relative risk = 1.3) and Background (relative risk = 1.4) categories were at increased risk of preterm birth. The risk of intrauterine growth retardation was not increased in any exposure category. The risk of infant death was increased in all Ranch Hand children, with the greatest increases in the High (relative risk = 4.5) and Background (relative risk = 3.2) categories. These patterns indicate that the increases in the relative risk of preterm birth and infant death may not be related to paternal dioxin level.

Levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin in 1,302 unexposed Air Force Vietnam-era veterans.

We summarize the distribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) in 1,302 Air Force veterans who serve as controls in a 20-year prospective epidemiologic study of health and exposure to herbicides and their dioxin contaminant in Air Force veterans of Operation Ranch Hand, the unit responsible for aerial spraying of Agent Orange and other herbicides in Vietnam. We present statistics summarizing the dioxin distribution overall and by stratum of age and body mass index of these veterans. The average dioxin measurement was 4.23 and the standard deviation was 2.53 parts per trillion. With 95% confidence, 99% of the distribution is less than or equal to 10.4 parts per trillion.

Serum dioxin, testosterone, and gonadotropins in veterans of Operation Ranch Hand.

We studied whether exposure to Agent Orange and its contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin), during the Vietnam War is related to current testosterone, follicle-stimulating hormone, luteinizing hormone, or testicular abnormalities, sperm count, sperm abnormalities, or testicular volume. The index subjects were veterans of-Operation Ranch Hand, the unit responsible for aerial herbicide spraying in Vietnam from 1962 to 1971. The referent cohort comprises Air Force veterans who served in Southeast Asia during the same period but were not involved with spraying herbicides. Referents were matched to Ranch Hands on date of birth, race, and military occupation. We found no consistent or meaningful association between serum dioxin levels and any of these outcome variables.

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.

Yellow lens effects upon visual acquisition performance.

Twenty subjects made a total of 400 threshold visual acquisitions of T-38 aircraft approaching from 9 miles out. Half of the acquisitions were made with the subjects wearing yellow ophthalmic filters, and the other half without filters. No overall statistically significant difference in acquisition performance due to the use of yellow filters was found.

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.

Coping and recovery styles in the Vietnam era prisoner of war.

Of the nearly 600 Vietnam War American prisoners of war (POWs), 332 were United States Air Force flyers who had suffered maltreatment, confinement, and boredom for months to years. We examined four coping styles of USAF POWs related to successful/unsuccessful coping and resistance stance during captivity and cognitive integration of the prisoner experience after repatriation. Findings indicate that no coping style is clearly associated with an increased risk of postrepatriation psychiatric morbidity. Postrepatriation MMPI scales indicate personality differences between individuals in the various coping groups.

The incidence of refractive anomalies in the USAF rated population.

A field survey was conducted to determine the percentage of U.S. Air Force pilots and navigators required to wear corrective lenses. A random sample survey stratified by major air commands (MAJCOMS) was designed to retrieve the data. Data requested included initial (entry) visual acuity and refractive error, and current visual acuity and prescription if glasses were required. Of 2,383 forms sent, 2,183 were returned completed. Analysis indicated that almost 20% of pilots and 50% of navigators are required to wear corrective lenses while flying. The percentages are rather consistent among MAJCOMS. Aircrew members who enter undergraduate pilot training with minus or plano refractive values are much more susceptible to develop myopia during their flying careers than those with plus refractive values.

Biochemical and histological analysis of "recurrent' macular corneal dystrophy.

A patient with macular corneal dystrophy who had a successful 6-mm corneal transplant 23 years ago underwent a second keratoplasty for marked irregular astigmatism. The excised button, which contained the original graft and a rim of host cornea, was divided into several portions. One portion was examined histologically, another portion was incubated in organ culture with radioactive precursors and the biosynthetically labeled products characterized, and a third portion was used for cell culture and karotype analysis. The results indicated that host stromacytes had not invaded the graft and that graft stromacytes had synthesized normal proteoglycans. Furthermore, although there was excessive synthesis of abnormal proteoglycan by host stromacytes and accumulation of this material in the host cornea, minor amounts of this material actually accumulated in the graft cornea, possible contributing to the astigmatism. A large transpant that would leave a minimum of host corneal tissue may be conductive to a longer-term good result in patients with macular corneal dystrophy.

The relationship of palato-gingival grooves to localized periodontal disease.

The purpose of this investigation was to determine the prevalence of the palato-gingival groove in maxillary incisor teeth and the health status of the lingual periodontal tissues adjacent to maxillary incisor teeth with and without the grooves. A total of 531 individuals aged 17 to 35 years were examined for the presence or absence of palato-gingival grooves in their maxillary incisor teeth. A Plaque Index (PII), Gingival Index (GI), and Periodontal Disease Index (PDI) were recorded for the lingual aspect of the four maxillary incisors. Tooth mobility was also recorded. The prevalence of the palato-gingival grooves in the 531 individuals examined was 8.5%. Of the 2,099 maxillary incisor teeth examined, 2.33% had a palato-gingival groove. Most of the palato-gingival grooves (93.8%) were in maxillary lateral incisor teeth. Statistical analyses revealed no differences in groove prevalence on the basis of sex or race. Results of the study also indicate that the palato-gingival groove is associated with poorer periodontal health as measured by the GI and PDI and more plaque accumulation as measured with the PII.

Pure follicular thyroid carcinoma: impact of therapy in 214 patients.

Records of 214 patients with pure follicular thyroid carcinoma were reviewed in detail to evaluate the circumstances of initial presentation and therapy on ultimate outcome. Mean followup was 8.8 yr. The only deaths directly attributable to the thyroid carcinoma occurred in patients with distant metastases at the time of presentation. There were 20 recurrences in the 182 patients considered free of disease after initial therapy. Overall recurrence rate was not affected by the presence of positive cervical nodes or extent of thyroid surgery. Postoperative recurrence rate was decreased by both radioiodine and thyroid-hormone therapy. Extensive histologic invasion of the capsule of the nodule and thyroid appeared to be associated with an increase in recurrence rate. Postoperative thyroid-hormone is required therapy in all patients with pure follicular thyroid carcinoma. Radioiodine therapy is indicated in patients with extensive invasion and we favor its use in all patients.

United States Air Force survey of dental needs, 1977: methodology and summary of findings.

This study represents the first, comprehensive baseline survey of dental needs conducted in the US Air Force. The air force population was stratified by command, base, and grade, and 5,805 active duty air force members, aged 17 to 57 years (mean, 27.83), were examined at random to determine their overall oral health status. Data were collected from 42 air force bases, representing 11 worldwide commands, which comprised 90% of all active duty members. This article presents the methodology for the study, a summary of the findings, and a comparison of dental needs among recruits and all other grades of active duty air force personnel. Results indicate a significant level of unmet dental needs in the US Air Force. For example, the average active duty individual presently serving in the air force would require eight hours and 48 minutes of chairside care to provide comprehensive treatment. Each entry level recruit would need an average of ten hours and 23 minutes of dental treatment.

Stressbreakers and the removable partial denture.

A laboratory study was designed to determine the effect of ""deactivation'' of stressbreakers on abutment tooth movement and ridge displacement. The Ticonium hidden-lock and the pin-Dalbo precision stressbreakers were tested. Results showed that ridge displacement was significantly decreased when the Dalbo was made rigid, and tooth movement was significantly decreased (during bilateral loading) when the hidden lock was made rigid.