Blockade of tubal patency following transcervical administration of polidocanol foam: initial studies in rhesus macaques.

OBJECTIVE: To demonstrate the feasibility of polidocanol foam (PF) as a nonsurgical method of female permanent contraception using a nonhuman primate model. STUDY DESIGN: Four groups of adult female rhesus macaques underwent either transcervical treatment with 5% PF directly into the uterine cavity, treatment with inert (methylcellulose, MF) foam or no treatment followed by removal of the reproductive tract for histologic evaluation. Untreated animals were included in Group 1 (n=3). Group 2 animals (n=4) were treated once with MF. Group 3 (n=7) received a single, and Group 4 (n=5) received multiple monthly treatments with PF; in these 2 groups, baseline tubal patency was assessed either laparoscopically by chromopertubation (CP) or by hysterosalpingography. RESULTS: Group 1 (untreated) and Group 2 (MF) animals had normal tubal histology. In contrast, Group 3 and 4 females treated with PF showed evidence of tubal damage. In Group 4, bilateral tubal blockade was noted on CP after two (n=2) or three (n=3) treatments. Histologic analysis confirmed complete tubal occlusion (loss of epithelium, fibrosis) in three of these animals, and one showed significant tubal damage localized to the intramural segment. Nontarget (cervix, vagina, endometrium, ovary) reproductive tissues were unaffected. While similar tubal changes were observed after a single treatment (Group 3), endometrial hemorrhage was also noted as an acute change. CONCLUSION: PF is a promising candidate agent for nonsurgical permanent female contraception. The histologic features of PF occlusion are confined to the intramural portion of the tube. IMPLICATIONS: This study in rhesus macaques supports further development of transcervical administration of PF as a nonsurgical approach to permanent contraception. A nonsurgical method could reduce risks and costs associated with surgical female sterilization and increase access to permanent contraception.

Further preliminary assessment of three human glioma cell lines as models of human astrocytic toxicity in vitro.

Three human astroglioma lines U251-MG, U373-MG and CCF-STTG1 have been evaluated further as possible models for astrocytotoxicity (GFAP and IL-6 release). The effects of bacterial lipopolysaccharide, chloroquine diphosphate and acrylamide were studied on GFAP expression and LPS, chloroquine diphosphate, ethanol, trimethyltin chloride (TMTC) and acrylamide were examined on interleukin-6 (IL-6) release in the U373-MG line only. At 4-h LPS elevated GFAP (17.0±5.0% P<0.05) above control in the U251-MG cell line only. Chloroquine diphosphate over 4h in the U251-MG line resulted in an increase in GFAP-IR to 20.3±4.2% and 21.1±4.1% above control levels 0.1µM (P<0.05) and 1µM (P<0.05) respectively. CQD was associated with decreases in MTT turnover, particularly after 24h incubation. With the U373-MG line, LPS (0.5µg/ml) increased IL-6 expression 640% above control (P<0.001), whilst chloroquine diphosphate (100µM), ethanol (10mM) and TMTC chloride (1µM) also increased IL-6. It is possible that batteries of astrocytic human glioma cell lines may be applicable to the sensitive evaluation of toxicants on astrogliotic expression markers such as GFAP and IL-6.

Assessment of the astrogliotic responses of three human astrocytoma cell lines to ethanol, trimethyltin chloride and acrylamide.

The astrogliotic responses of the CCF-STTG1, U251-MG, and U373-MG human astrocytoma lines were determined after exposure to ethanol, trimethyltin chloride (TMTC), and acrylamide over 4, 16, and 24h. Basal glial fibrillary acidic protein (GFAP) expression in the U-251MG and U373-MG cells was 10-fold greater than the CCF-STGG1 line. Ethanol treatment over 24h, but not at 4 and 16h, resulted in significant increases in GFAP in all three glioma lines at sub-cytotoxic levels; the GFAP responses in the CCF-STTG1 line were the most sensitive, as concentrations of 0.1 and 1mM led to increases in GFAP expression compared with control of 56.8+/-15.7 and 58.9+/-11.5%, respectively (P<0.05). Treatment with TMTC (1 microM) over 4h showed elevated GFAP expression in the U251-MG cell line to 28.0+/-15.7% above control levels (P<0.01), but not in the other U373-MG or CCF-STTG1 cells. At 4h, MTT turnover was markedly increased compared with control, particularly in the U373-MG line at concentrations as low as 1 microM (17.1+/-2.3%; P<0.01). TMTC exposure over 16 and 24h resulted in reduction in GFAP expression in all three lines at concentrations; at 24h incubation, the reduction was >50% (P<0.01). There were no changes in GFAP expression or MTT turnover in response to acrylamide except at the highest concentration ranges of 10-100 mM. This study underlines the significance of period of exposure, as well as toxin concentration in astrocytoma cellular response to toxic pressure.