On talc translocation from the vagina to the oviducts and beyond.

The objective of this study was to investigate whether multiple vaginal depositions of neutron-activated talc in the cynomolgus monkey result in the translocation of this material to the uterus and beyond. Within a 45-day period, six monkeys received 30 applications of 125 mg neutron-activated talc, suspended in 0.3 ml physiological saline solution containing 1% carboxymethyl cellulose as a suspending agent. The suspension was deposited in the posterior vaginal fornix of the sedated monkeys. Two days after the final talc application, the animals were anaesthetized. Abdominal lavage was performed and the lavage fluid collected for gamma-ray analysis. Also collected for gamma-ray analysis were the following tissues/organs: ovaries, oviducts, uterus, and vagina with cervix. Six untreated control monkeys underwent the same procedures. The radioisotopes 46Sc, 60Co, 59Fe and 51Cr in the activated talc served as tracers. Only the samples containing vagina and cervix from the dosed monkeys contained varying quantities of talc. This demonstrates that no measurable quantities of talc, deposited by multiple applications in the vaginal fornix of the cynomolgus monkey, translocated to the uterus or beyond.

Do particles translocate from the vagina to the oviducts and beyond?

To investigate whether particles deposited in the vagina translocate to the oviducts, 0.3 ml of a 4% bone black suspension was deposited in the posterior vaginal fornix of each of five cynomolgus monkeys (Macaca fascicularis) during their mid-menstrual cycle. Simultaneously, each animal received 10 units of oxytocin by intramuscular injection. The oviducts of three animals were removed 1 hr after administration of the bone black, while those of the remaining two animals were removed 72 hr after dosing. The removed oviducts were flushed with Hank's solution and then with collagenase solution. The solutions were collected in clean vials and filtered. The filters were examined for bone black particles by light microscopy, as were filters through which solution blanks (negative controls) had been passed. Particles resembling bone black were found on all filters. There were no appreciable differences in the number or shape of these particles between the solution-blank filters and the oviduct-flush filters. The particles on both the solution-blank filters and on the oviduct-flush filters probably originated from environmental contamination by ubiquitous carbon particles. While these results suggested that no translocation took place, translocation could not be ruled out with certainty in the absence of quantitative analyses. A more definitive pilot study was then conducted with two dosed monkeys and one control, using talc labelled by neutron activation to circumvent the problem of environmental contamination. Gamma-Ray analysis of tissue and peritoneal lavage samples for the radionuclides 46Sc, 59Fe and 60Co indicated that no measurable quantities (i.e. greater than 0.5 micrograms) of talc translocated from the deposition site in the vagina to the uterine cavity and beyond.

Mount st. Helens ash from the 18 may 1980 eruption: chemical, physical, mineralogical, and biological properties.

Samples of ash from the 18 May 1980 eruption of Mount St. Helens were collected from several locations in eastern Washington and Montana. The ash was subjected to a variety of analyses to determine its chemical, physical, mineralogical, and biological characteristics. Chemically, the ash samples were of dacitic composition. Particle size data showed bimodal distributions and differed considerably with location. However, all samples contained comparable amounts of particles less than 3.5 micrometers in diameter (respirable fraction). Mineralogically, the samples ranged from almost totally glassy to almost totally crystalline. Crystalline samples were dominated by plagioclase feldspar (andesine) and orthopyroxene (hypersthene), with smaller amounts of titanomagnetite and hornblende. All but one of the samples contained from less than 1 percent to 3 percent free crystalline silica (quartz, trydimite, or cristobalite) in both the bulk samples and 1 to 2 percent in the fractions smaller than 3.5 micrometers. The long-lived natural radionuclide content of the ash was comparable to that of crustal material; however, relatively large concentrations of short-lived radon daughters were present and polonium-210 content was inversely correlated with particle size. In vitro biological tests showed the ash to be nontoxic to alveolar macrophages, which are an important part of the lungs' natural clearance mechanism. On the basis of a substantial body of data that has shown a correlation between macrophage cytotoxicity and fibrogenicity of minerals, the ash is not predicted to be highly fibrogenic.