Combination chemotherapy of intraperitoneal carboplatin and intravenous paclitaxel in suboptimally debulked epithelial ovarian cancer.

The objective of this study was to retrospectively assess the efficacy and safety of combination chemotherapy of intraperitoneal (IP) carboplatin and intravenous (IV) paclitaxel in suboptimally debulked ovarian cancer. Between March 1998 and March 2006, 44 patients with histologically confirmed epithelial ovarian carcinoma or peritoneal carcinoma with a residual mass greater than 1 cm received combination chemotherapy of IV paclitaxel and IP carboplatin. Administration of IV paclitaxel at 175 mg/m(2) immediately followed by IP carboplatin at an area under the curve of 6 was scheduled every 3 weeks for at least six cycles. The diagnosis and stage were ovarian carcinoma stage II in 8, III in 25, and IV in 6 cases, and peritoneal carcinoma stage III in 5 cases. Eighty-three percent of patients completed more than six cycles of chemotherapy. The incidences of grade 3/4 hematologic toxicities were 41 (93%) for neutrocytopenia, 10 (41%) for thrombocytopenia, and 18 (23%) for anemia. Observed grade 3/4 nonhematologic toxicities were 1 (2%) for allergy, 1 (2%) for fatigue, 1 (2%) for vomiting, 1 (2%) for liver dysfunction, and 4 (9%) for peripheral neuropathy. Two patients (5%) encountered catheter problems (one obstruction and one infection). Overall response rate was 80% (16 complete response, 19 partial response, 3 stable disease, and 6 progressive disease). Median progression-free survival and overall survival were 24 and 31 months, respectively. Combination chemotherapy of IP carboplatin and IV paclitaxel is effective and safe in suboptimally debulked ovarian cancer, and further evaluation is warranted.

Effects of recombinant human soluble thrombomodulin (rhs-TM) on a rat model of disseminated intravascular coagulation with decreased levels of plasma antithrombin III.

We reported that recombinant human soluble thrombomodulin (rhs-TM) is effective for disseminated intravascular coagulation (DIC) in vivo, in mice and rats. In the present work, we investigated the effects of decreased plasma antithrombin III (ATIII) levels on anticoagulant effects of rhs-TM, as compared to findings with heparin, of which effect is lowered by the decreased plasma ATIII levels in patients with DIC. Rat plasma ATIII levels decreased when we mixed plasma with anti-rat ATIII antibody and the potential of heparin to prolong APTT or PT was markedly diminished. The potential of rhs-TM to prolong APTT and PT was not affected. In rats injected with anti-rat ATIII antibody, plasma ATIII levels decreased immediately. When the rats were infused with tissue factor (TF), DIC was induced. At doses of rhs-TM and heparin which were equally effective at inhibiting the decrease in platelet count and fibrinogen level in control rats treated with TF, only rhs-TM remained effective in preventing DIC in rats with reduced ATIII levels. Heparin was not effective when administered to these rats with reduced ATIII levels. Therefore, rhs-TM effectively inhibits coagulation independent of ATIII levels, in contrast to heparin, which depends on the ATIII level.

Recombinant human soluble thrombomodulin delivers bounded thrombin to antithrombin III: thrombomodulin associates with free thrombin and is recycled to activate protein c.

Recombinant human soluble thrombomodulin (rhs-TM), having no transmembrane domain or chondroitin sulfate, was expressed in Chinese hamster ovary cells. Interactions between rhs-TM, thrombin (Th), protein C (PC) and antithrombin III (ATIII) were studied. Equilibrium between rhs-TM and Th had no detectable time lag in clotting inhibition (Kd = 2.6 nM) or PC activation (Kd = 22 nM), while ATIII inhibited Th at a bimolecular rate constant = 5,200 M-1s-1 (Kd < 0.2 nM). A mixture of ATIII, Th and rhs-TM showed that ATIII reacted with Th slower than rhs-TM, whose presence did not affect the reaction between ATIII and Th. In a mixture of rhs-TM, ATIII and PC, the repeated addition of Th caused the repeated activation of PC; which was consistent with the simulation based on the assumption that rhs-TM is recycled as a Th cofactor. From these results, we concluded that upon inhibition of the rhs-TM-Th complex by ATIII, rhs-TM is released to recombine with free Th and begins to activate PC, while the Th-ATIII complex does not affect rhs-TM-Th equilibrium.

Evidence that the protein C activation pathway amplifies the inhibition of thrombin generation by recombinant human thrombomodulin in plasma.

Thrombomodulin (TM) is a cofactor for the thrombin-catalyzed activation of anticoagulant protein C. However, we have no evidence that thrombomodulin actually activates protein C during blood coagulation processing, nor do we know whether this activated protein C acts as an anticoagulant. We studied the inhibitory action of recombinant human soluble TM (rhs-TM) on thrombin generation in whole plasma. Human plasma was activated with small amounts of tissue factor using phospholipid vesicles in place of activated platelets. Thrombin generation was observed. The addition of only 2 nM of rhs-TM prevented rapid generation of thrombin and reduced the total amount of thrombin generated. In order to study the influence of the protein C activation pathway on this inhibitory action of rhs-TM, protein C-depleted plasma was used. rhs-TM had little inhibitory effect on protein C-depleted plasma. However, the addition of protein C caused a delay in thrombin generation and a reduction of the maximum thrombin concentration. We concluded that the anticoagulant activity of rhs-TM was amplified by the protein C activation pathway.