In vitro and in vivo evaluation of polymer hydrogels for hemorrhage control.

In vitro and in vivo experimentation of various synthetic polymer hydrogels was conducted to establish some of the integral material properties that influence hemostasis. In vitro swelling experiments suggested that positive electrostatic charge was a key determinant of the ability of a polymer hydrogel to absorb physiological fluids, e.g. human plasma and blood. In vitro testing using unadulterated sheep blood suggested positive electrostatic charge and crosslink density were key determinants of the ability of a material to induce or enhance clot formation. Hydrogel formulations composed of higher amounts of positive electrostatic charge and lower crosslink density were able to effectively induce and enhance clot formation in the presence of a coagulation cascade activator. In vivo experimentation confirmed that hydrogels containing higher electrostatic charge and low crosslink density are more effective at fostering the formation of a robust hemostatic plug to control blood loss.

Apoptosis and cell proliferation correlated with tumour grade in peritoneal fluids of patients with serous ovarian cancer.

OBJECTIVE: Apoptosis and cell proliferation in peritoneal fluids of patients with ovarian serous adenocarcinoma have not been well described in cytology. To investigate the contribution of cell death to the growth of this tumour we analysed both apoptosis and cell proliferation in peritoneal fluids of patients with ovarian serous adenocarcinoma. METHODS: We studied 40 tumours from 40 patients with ovarian serous adenocarcinoma. Twelve tumours were high grade, 13 were moderately differentiated and 15 were poorly differentiated. The detection of DNA fragments in situ using the terminal deoxyribonucleotidy transferase (TDT)-mediated dUTP-digoxigenin nick-end labelling (TUNEL) assay was applied to investigate active cell death (apoptosis), and the MIB-1 antigen was used to investigate cell proliferation. RESULTS: The TUNEL indices were 0.29 ± 0.05, 0.79 ± 0.10 and 2.1 ± 0.90 in Grade I, Grade II and Grade III ovary carcinomas, respectively. The MIB-1 antigen labelling indices were 6.5 ± 0.09, 12.9 ± 3 and 25.8 ± 6.2, respectively, in the same order of tumour differentiation. The differences in both TUNEL and MIB-1 labelling indices were statistically significant between Grade I, Grade II and Grade III carcinomas and there was a positive correlation between the two indices (P < 0.001). CONCLUSIONS: Apoptosis and cell proliferation increased as the grade of tumour increased in ovarian serous adenocarcinoma, suggesting a rapid turnover of the tumour cells in tumours of higher grade, and may play an important role in the growth and the extension of such cancer cells in the peritoneal cavity.

Immunoreactive beta-endorphin in sheep ovary.

Although the ovarian production of sex steroids is of obvious physiological importance, recent studies suggest that peptides such as oxytocin, relaxin and inhibin are also synthesized in the ovary. We report here the presence of immunoreactive (ir) beta-endorphin, ir-adrenocorticotropic hormone (ACTH) and presumptive high molecular weight forms of both in extracts of sheep ovary, consistent with ovarian production from a common precursor. Our findings suggest that beta-endorphin and ACTH are produced and secreted by the follicular cells, and that their production may be related to the oestrous cycle.

Panax ginseng and Eleuthrococcus senticosus extracts--in vitro studies on binding to steroid receptors.

We have examined the binding of 44% saponin from Panax ginseng, and extracts from Eluthrococcus senticosus (Siberian ginseng) to classical steroid receptors in vitro. Both extracts had demonstrable affinity for progestin, mineralocorticoid and glucocorticoid receptors; the Siberian ginseng also bound to estrogen receptors. Highest affinity binding was to glucocorticoid receptors, with an approximate Ki of 8 x 10(-6) M for Panax ginseng. Such interactions may explain the reported glucocorticoid-like effects of ginseng in vivo.