Continuing concern regarding the potential health and environmental effects of depleted uranium and lead has resulted in many countries adding tungsten alloy (WA)-based munitions to their battlefield arsenals as replacements for these metals. Because the alloys used in many munitions are relatively recent additions to the list of militarily relevant metals, very little is known about the health effects of these metals after internalization as embedded shrapnel. Previous work in this laboratory developed a rodent model system that mimicked shrapnel loads seen in wounded personnel from the 1991 Persian Gulf War. In the present study, we used that system and male F344 rats, implanted intramuscularly with pellets (1 mm × 2 mm cylinders) of weapons-grade WA, to simulate shrapnel wounds. Rats were implanted with 4 (low dose) or 20 pellets (high dose) of WA. Tantalum (20 pellets) and nickel (20 pellets) served as negative and positive controls, respectively. The high-dose WA-implanted rats (n = 46) developed extremely aggressive tumors surrounding the pellets within 4–5 months after implantation. The low-dose WA-implanted rats (n = 46) and nickel-implanted rats (n = 36) also developed tumors surrounding the pellets but at a slower rate. Rats implanted with tantalum (n = 46), an inert control metal, did not develop tumors. Tumor yield was 100% in both the low- and high-dose WA groups. The tumors, characterized as high-grade pleomorphic rhabdomyosarcomas by histopathology and immunohistochemical examination, rapidly metastasized to the lung and necessitated euthanasia of the animal. Significant hematologic changes, indicative of polycythemia, were also observed in the high-dose WA-implanted rats. These changes were apparent as early as 1 month postimplantation in the high-dose WA rats, well before any overt signs of tumor development. These results point out the need for further studies investigating the health effects of tungsten and tungsten-based alloys.

The present experiments were carried out to determine the effects of energy deposition from energetic iron (56Fe particles, an important component of cosmic rays) on motor behavioral performance and to determine if the observed deficits were caused by alterations in the neostriatum (an important motor control area). Neostriatal function was assessed with two correlated parameters, i.e., motor behavioral performance (wire suspension task), and oxotremorine-enhanced K(+)-evoked release of dopamine from perifused striatal slices. Rats were exposed to one of several doses of 56Fe-particle irradiation (0.10-1.0 Gy) and tested on a wire suspension task at 3-180 days postirradiation. Results indicated that profound decrements occurred in both of these indices. The effects on K(+)-evoked release of dopamine were evident for as long as 180 days after irradiation, and a subsequent experiment indicated that these effects appeared as early as 12 h postirradiation. Since similar findings have been observed in aged rats, the results are discussed in terms of these particles producing a possible accelerated striatal aging effect.

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Two-thirds of all meningiomas and four-fifths of intraspinal and sphenoidal meningiomas occur in women. Meningiomas frequently enlarge or become symptomatic during pregnancy or during the luteal phase of the menstrual cycle. There is an increased incidence of meningiomas in women with breast carcinoma. In a series of 23 patients with meningiomas, the authors assayed biopsy specimens of the tumor for the presence of estrogen (ER) and progesterone (PR) receptors, using glycerol density gradient centrifugation and dextran-coated charcoal techniques. Significant levels of ER were found in only 17% of the patients, while significant PR levels were detected in 39%. Only one of the 16 tumors from female patients had significant ER levels, whereas three of the seven tumors from men had significant ER levels. Eight of the 16 tumors in women had significant PR levels, whereas only one of the seven tumors in men had a significant PR level. Thus, three out of four tumors with definite ER were from men, whereas eight of nine tumors with definite PR were from women. Of the eight women whose tumors contained PR, three were premenopausal and five postmenopausal. The single tumor with high levels of PR in the male patient was histologically atypical. The results of this series were compared with six published series of sex steroid assays in meningiomas. These seven series were divided into two groups: one group included two reports from the same laboratories in France, and the other the remaining five reports. Much higher percentages of both ER- and PR-positive tumors were reported from the French group. The authors suggest that this discrepancy may be due to the use of preoperative glucocorticoid therapy in the series from the United States. Since meningiomas are known to enlarge during periods when levels of circulating progestins are high, the presence of significant quantities of PR in a high percentage of tumors may have therapeutic implications for recurrent, malignant, or incompletely excised tumors, or for medically fragile patients. Conversely, since meningiomas are not known to enlarge during the proliferative phase of the menstrual cycle or with exogenous estrogen therapy, the small number of tumors positive for ER may indicate that ER lacks clinical significance. High levels of PR found in a small group of histologically aggressive tumors in several series may indicate that hormonal therapy may be especially useful in this difficult subset of patients.

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