Trichloroethylene health risk assessment: a new and improved process.

Trichloroethylene (TCE), an environmental contaminant of National concern, is the focus of a new health risk assessment process incorporating the Proposed Cancer Risk Assessment Guidelines. This paper describes not only how TCE became an environmental problem for the Air Force, but also details the new Risk Assessment process envisioned by the Environmental Protection Agency's (EPA) National Center for Environmental Assessment (NCEA). Insights on epidemiological evaluations, both past and future, and their impact on the cancer classification of TCE are discussed. Examples of how physiologically based pharmacokinetics and dose-response characterization described in the new Cancer Guidelines are applied to TCE are provided. In addition, a variety of modeling techniques are discussed for the development of reference doses (oral exposure) and reference concentrations (inhalation exposures) for TCE. Finally, the role of risk communication is included. This new process provides an example of how interagency (EPA, Department of Defense. Department of Energy) and extramural (industry, academia) partnerships can provide greater gains to the nation, as a whole, than any of the parts on their own.

Travelers' diarrhea among United States military personnel during joint American-Egyptian armed forces exercises in Cairo, Egypt.

A study was conducted of travelers' diarrhea in a United States military population on deployment in Cairo, Egypt, during July and August 1987. Acute diarrhea requiring medical attention developed in 183 (4%) of 4,500 troops. A possible etiologic agent was identified in 49% of all diarrhea cases. Enteric pathogens associated with cases of diarrhea included: Enterotoxigenic Escherichia coli (17% ST-producers, 13% LT-producers, and 3% LT/ST-producers); Shigella (9%); Campylobacter spp. (2%); Salmonella (2%); and Vibrio cholerae non-01 serogroup (2%). Other enteric pathogens isolated from one episode each of diarrhea included Aeromonas hydrophila group, Plesiomonas shigelloides, and Bacillus cereus. Yersinia enterocolitica, enteroinvasive E. coli, intoxications by Clostridium perfringens and Clostridium difficile, and pathogenic enteric parasites were not found in any of the 183 patients with diarrhea. A survey of military personnel not requesting medical care indicated that up to 40% of troops may have had diarrhea during this deployment. Acute gastroenteritis is a potential cause of substantial morbidity in U.S. military personnel deployed to Egypt.

Oocyte maturation inhibitor activity in human follicular fluid: quantitative determination in unstimulated and clomiphene citrate- and human menopausal gonadotropin-stimulated ovarian cycles.

Since removal of the oocyte from the intrafollicular milieu allows meiotic resumption and germinal vesical breakdown to proceed, the concept of an intrafollicular oocyte maturation inhibitor (OMI) has evolved. Accordingly, we asked the following questions: Is there OMI activity in human follicular fluid? Does OMI activity change with ovarian hyperstimulation? and Does OMI activity correlate with oocyte fertilization or the concentration of steroids in the corresponding follicular fluid? Fresh cumulus enclosed porcine oocytes from small follicles were incubated with human follicular fluid aspirates from normally menstruating patients with or without treatment: unstimulated follicles (N = 10), clomiphene citrate (150 mg/day) (N = 10)-treated cycles, and human menopausal gonadotropin (hMG) (N = 12)-treated cycles. A lyophylized porcine follicular fluid standard and serum-free culture media were used as positive and negative controls, respectively. After a 40-hr incubation with test materials, the oocytes were fixed, stained, and evaluated for oocyte maturation as determined by germinal vesical breakdown. Human follicular fluid, estradiol, progesterone, androstenedione, and testosterone levels were determined by radioimmunoassay. The 50% inhibitory dose (ID50) for OMI activity in follicular fluid from untreated, spontaneously menstruating women was less than that for follicular fluid from clomiphene-stimulated patients, which was less than that for follicular fluid from hMG-stimulated patients. The difference between OMI values from untreated and hMG-stimulated follicular fluids was statistically significant. Human oocytes removed from follicular fluid with higher OMI activity tended not to fertilize in vitro compared to the relatively lower OMI activity present in follicular fluid yielding oocytes which did fertilize.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunologic responsiveness and safety associated with the Coccidioides immitis spherule vaccine in volunteers of white, black, and Filipino ancestry.

A trial of the killed Coccidioides immitis spherule vaccine was undertaken with 151 healthy skin test negative adult volunteers and controls to evaluate the safety of selected regimens, the induction of humoral and cell-mediated immune responses, and to determine if there were immunogenetic differences in these responses. The vaccine was given as three intra-deltoid doses over 8 weeks. No severe systemic symptoms were noted, although 3% of 3.5 mg doses (but no 1.75 mg doses) were associated with severe local reactions. Half the vaccinees had skin test conversions, which generally persisted greater than or equal to 6 months, two-thirds showed boosting of lymphocyte transformation in vitro, and 16% given three 3.5 mg doses developed antibody. There was an association between degree of local adverse vaccine reaction and immunostimulation, and a trend to immune response in persons of O blood type and with some HLA phenotypes. There was no evidence of deficient response to vaccination in subpopulations known to respond to coccidioidal infection poorly. A regimen of three 1.75 mg doses appears to be safe and without reduced immunogenicity, and there is no evidence dosage modification for certain subpopulations would be necessary in efficacy studies.

Anaplastic seminoma: an analysis of 77 patients.

Over a 28 year period, 77 patients with early stage anaplastic seminoma of the testis were treated by orchiectomy and lymphatic irradiation at three Army medical centers. With a median follow-up of 97 months, the 10 year actuarial survival is 96% of Stage I patients and 87% for Stage II patients. For patients with Stage I anaplastic seminoma no survival advantage can be demonstrated for adding mediastinal and supraclavicular irradiation versus para-aortic and pelvic irradiation alone. The addition of retroperitoneal lymphadenectomy to lymphatic irradiation increased the frequency of major gastrointestinal complications without significantly improving survival. Patients with anaplastic seminoma and elevated serum beta-subunit human chorionic gonadotrophin levels have a poor prognosis and should be considered for adjuvant combination chemotherapy. Anaplastic seminoma of the testis has a similar clinical presentation, response to therapy and prognosis compared to typical seminoma and should be managed in the same way.

New thoughts concerning xanthogranulomatous pyelonephritis (X-P).

A clinical and roentgenographic analysis of 13 patients with pathologically proved xanthogranulomatous pyelonephritis (X-P) has demonstrated that many previously accepted truisms associated with this disease may not be valid. As a result of this study it is suggested that X-P: 1. Does have a prominant female distribution. 2. May arise relatively acutely. 3. Can be associated with a well-functioning kidney. 4. May destroy the kidney and collecting system. 5. Does not demonstrate neovascularity. 6. Can be distinguished angiographically from hypernephroma. 7. May be associated with diabetes. Other important facts were again observed: 1. X-P is still often associated with staghorn calculi and urinary tract obstruction. 2. Proteus mirabilis is the main offending organism.