Amplification in human breast cancer of a gene encoding a c-myc mRNA-binding protein.

The coding region determinant-binding protein (CRD-BP) binds in vitro to c-myc mRNA and is thought to stabilize the mRNA and increase c-Myc protein abundance. The CRD-BP gene has 15 exons and 14 introns, is single-copy, and is located on chromosome 11 in mice and 17 in humans, close to HER-2/neu. The CRD-BP gene is moderately amplified in 12 of 40 human breast cancers; it is highly amplified in 2 others (14.4 and 20 copies). Despite their proximity, CRD-BP and HER-2/neu genes can be amplified independently. Amplification of a gene that might up-regulate c-Myc abundance could accelerate breast cancer.

Risk factors for mental disorder hospitalization after the Persian Gulf War: U.S. Armed Forces, June 1, 1991-September 30, 1993.

Effects of Persian Gulf War (August 2, 1990-July 31, 1991) and Gulf War occupation on post-War hospitalization risk were evaluated through Cox proportional hazards modeling. Active-duty men (n = 1,775,236) and women (n = 209,760) in the Army, Air Force, Navy, and Marine Corps had 30,539 initial postwar hospitalizations for mental disorders between June 1, 1991 and September 30, 1993. Principal diagnoses in the Defense Manpower Data Center hospitalization database were grouped into 10 categories of ICD-9-CM codes. Gulf War service was associated with significantly greater risk for acute reactions to stress and lower risk for personality disorders and adjustment reactions among men. Personnel who served in ground war support occupations (men and women) were at greater risk for postwar drug-related disorders. Men who served in ground war combat occupations were at higher risk for alcohol-related disorders. Longitudinal studies of health, hospitalization, and exposure beginning at recruitment, are needed to better understand how exposure to combat affects the mental health of military personnel.

The postwar hospitalization experience of Gulf War Veterans possibly exposed to chemical munitions destruction at Khamisiyah, Iraq.

Using Department of Defense hospital data, the authors examined the postwar hospitalization experience from March 1991 through September 1995 of US Gulf War veterans who were near Khamisiyah, Iraq, during nerve agent munition destruction in March 1991. Multiple sources of meteorologic, munition, and toxicology data were used to circumscribe geographic areas of low level, vaporized nerve agent for 4 days after the destruction. Plume estimates were overlaid on military unit positions, and exposure was estimated for the 349,291 US Army Gulf War veterans. Exposure was classified as not exposed (n = 224,804), uncertain low dose exposure (n = 75,717), and specific estimated subclinical exposure (n = 48,770) categorized into three groups for dose-response evaluation. Using Cox proportional hazard modeling, the authors compared the postwar experiences of these exposure groups for hospitalization due to any cause, for diagnoses in 15 unique categories, and for specific diagnoses an expert panel proposed as most likely to reflect latent disease from such subclinical exposure. There was little evidence that veterans possibly exposed to the nerve agent plumes experienced unusual postwar morbidity. While there were several differences in hospitalization risk, none of the models suggested a dose-response relation or neurologic sequelae. These data, having a number of limitations, do not support the hypothesis that Gulf War veterans are suffering postwar morbidity from subclinical nerve agent exposure.

Biomonitoring of United States Army soldiers serving in Kuwait in 1991.

Biomarkers of polycyclic aromatic hydrocarbon (PAH) exposure and genetic biomarkers of potential cancer susceptibility were determined in a group of United States Army soldiers who were deployed to Kuwait and Saudi Arabia in 1991 in the aftermath of the Persian Gulf War. Because hundreds of oil well fires were still burning, there was concern that ground troops stationed in Kuwait might be exposed to high levels of PAHs and other toxicants. The United States Army Environmental Hygiene Agency monitored air and soil for ambient PAHs. In addition, a group of 61 soldiers was involved in the biomonitoring study reported here. These soldiers kept diaries of daily activities and provided blood and urine samples in Germany (June) before deployment to Kuwait, after 8 weeks in Kuwait (August), and 1 month after the return to Germany (October). Here we present data for PAH-DNA adducts measured by immunoassay in blood cell DNA samples obtained at all three sampling times from 22 soldiers and bulky aromatic adducts measured by 32P-postlabeling in blood cell DNA samples from 20 of the same soldiers. Urinary 1-hydroxypyrene-glucuronide levels were determined by synchronous fluorescence spectrometry in a matched set of samples from 33 soldiers. Contrary to expectations, environmental monitoring showed low ambient PAH levels in the areas where these soldiers were working in Kuwait. For both DNA adduct assays, levels were the lowest in Kuwait in August and increased significantly after the soldiers returned to Germany (October). Urinary 1-hydroxypyrene-glucuronide levels were also lowest in Kuwait and highest in Germany, but the differences were not statistically significant. The PAH-exposure biomarker levels were not significantly influenced by polymorphic variations of CYP1A1 (MspI) and glutathione S-transferases M1 and T1. Overall, the data suggest that this group of soldiers was not exposed to elevated levels of PAHs while deployed in Kuwait.

Measurement of reflectance by gas ionization.

In an attempt to improve the accuracy of reflectance determinations, particularly from high vapor pressure samples, we have built and tested a double ionization chamebr which measures the ionization from a photon beam in the vapor or added gas before and after reflection. The photon beam strikes the sample at nearnormal incidence after passing through an oblong ionization chamber containing two collector wires. These are connected to one side of an electrometer-ratiometer of new design. A similar geometry is used for the specularly reflected beam, with the wires here connected to the other side of the ratiometer. A potential of 20 V on the sample is found to be sufficient to prevent the large photoelectric current from the sample from entering the chambers for photon energies to 26 eV. A sitnple calculation shows that the current ratio should decline exponentially with pressure in the operating pressure range from 100 microm to 5000 microm. Extrapolation of the data to zero pressure yields the sample reflectance. In testing, we found the reflectance to be 12.47% at 841 A for an evaporated gold film using a filling gas of air.