Can prepartum thromboelastometry-derived parameters and fibrinogen levels really predict postpartum hemorrhage?

BACKGROUND

Decreased postpartum rotational thromboelastometric parameters of coagulation (ROTEM®) and fibrinogen levels have been associated with postpartum hemorrhage (PPH). However, the predictive power of prepartum ROTEM® parameters and fibrinogen levels (Fbgpre) for PPH remains unknown.

METHODS

This prospective observational pilot study included 217 healthy pregnant women. Maximum clot firmness (FIBTEM-MCF), fibrinogen levels and standard coagulation parameters were measured upon admission to the delivery room for labor and within 1 h after vaginal delivery. Blood loss was measured with a calibrated collecting drape during the third stage of labor. PPH was defined as blood loss ≥500 mL. Predictors for bleeding were identified via receiver operating characteristic analyses and bivariate and multivariate regression analyses.

RESULTS

Women with and without PPH did not differ in median FIBTEM-MCF [23 mm (25th percentile 20 mm, 75th percentile 26 mm) vs. 23 mm (19 mm, 26 mm), respectively; P=0.710] or mean Fbgpre (4.57±0.77 g/L vs. 4.45±0.86 g/L, respectively; P=0.431). Blood loss and prepartum coagulation parameters were not correlated (FIBTEM-MCF, rs=-0.055, P=0.431; Fbgpre, rs=-0.017, P=0.810). The areas under the curves (predictive power for PPH) for FIBTEM-MCF and Fbgpre and were 0.52 (0.41-0.64, P=0.699) and 0.53 [95% confidence interval (95% CI) 0.40-0.65, P=0.644], respectively. Neither FIBTEM-MCF nor Fbgpre was associated with PPH. However, primiparity [odds ratio (OR) 4.27, 95% CI 1.32-13.80, P=0.015) and urgent cesarean section (2.77, 1.00-7.67, P=0.050) were independent predictors of PPH.

CONCLUSIONS

ROTEM® parameters, Fbgpre and postpartum blood loss were not associated, nor did these factors predict PPH. Sufficiently powered prospective studies are needed to confirm these results.

Evaluation of measured postpartum blood loss after vaginal delivery using a collector bag in relation to postpartum hemorrhage management strategies: a prospective observational study

AIM

To evaluate the incidence of postpartum hemorrhage (PPH) and severe PPH via routine use of a pelvic drape to objectively measure blood loss after vaginal delivery in connection with PPH management.

METHODS

This prospective observational study was undertaken at the obstetrical department of the Charité University Hospital from December 2011 to May 2013 and evaluated an unselected cohort of planned vaginal deliveries (n=1019 live singletons at term). A calibrated collecting drape was used to meassure blood loss in the third stage of labor. PPH and severe PPH were defined as blood loss ≥500 mL and ≥1000 mL, respectively. Maternal hemoglobin content was evaluated at admission to delivery and at the first day after childbirth.

RESULTS

During the study period, 809 vaginal deliveries were analysed. Direct measurement revealed a median blood loss of 250 mL. The incidences of PPH and severe PPH were 15% and 3%, respectively. Mean maternal hemoglobin content at admission was 11.9±1.1 g/dL, with a mean decrease of 1.0±1.1 g/dL. Blood loss measured after vaginal delivery correlated significantly with maternal hemoglobin decrease.

CONCLUSIONS

This study suggests that PPH incidence may be higher than indicated by population-based data. Underbuttocks drapes are simple, objective bedside tools to diagnose PPH. Blood loss should be quantified systematically if PPH is suspected.

Transactivation of the metallothionein promoter in cisplatin-resistant cancer cells: a specific gene therapy strategy

BACKGROUND

Cisplatin (cis-diamminedichloroplatinum) is one of the most active agents against a broad range of malignancies, including ovarian cancer. Cisplatin resistance appears to be associated with several molecular alterations, including overexpression of metallothionein, a metal-binding protein. In the present study, we attempted to take advantage of metallothionein overexpression to overcome cisplatin resistance.

METHODS

Using a virus-free system (liposomes), we sought to express the suicide gene, thymidine kinase (TK), driven by the promoter of the human metallothionein IIa (hMTIIa) gene using the pMT-TK plasmid. We used cisplatin-resistant human ovarian carcinoma cells as a model.

RESULTS

We first analyzed metallothionein expression using a ribonuclease protection assay. In comparison to parental cells, the cisplatin-resistant cells were found to have increased expression of metallothionein messenger RNA (mRNA). Metallothionein overexpression in these cells was not associated with an increased copy number of the hMTIIa gene or with different transfection efficiencies. Furthermore, we showed by reverse transcription-polymerase chain reaction analysis that transfection of the pMT-TK plasmid results in a 56-fold higher expression of thymidine kinase mRNA in cisplatin-resistant cells compared with parental cells, consistent with increased metallothionein promoter-mediated transactivation in the cisplatin-resistant cells. Transfection of resistant cells with pMT-TK or a control plasmid (pCD3-TK) resulted in a marked sensitization to ganciclovir, with a 50% cell growth-inhibitory concentration (IC(50)) of 20 microg/mL and 9 microg/mL, respectively. Transfections of the cisplatin-sensitive cells resulted in no sensitization to ganciclovir with pMT-TK (IC(50) 200 microg/mL) and a high sensitization with pCD3-TK (IC(50) = 6 microg/mL).

CONCLUSION

These studies suggest that pMT-TK gene therapy may provide an alternative treatment for cisplatin-refractory ovarian tumors.

Amplification of 4q21-q22 and the MXR gene in independently derived mitoxantrone-resistant cell lines

Molecular cytogenetic studies were conducted on three multidrug-resistant cancer sublines which are highly resistant to the chemotherapeutic agent mitoxantrone, an anthracenedione. The three independently selected sublines were derived by exposure to mitoxantrone or Adriamycin and do not overexpress MDR1 or MRP. Two sublines, MCF-7 AdVp3000 and MCF-7 MX, showed an amplification peak at 4q21-q22, as demonstrated by comparative genomic hybridization (CGH), while the third, S1-M1-80, did not. FISH using a whole chromosome 4 paint demonstrated multiple rearrangements involving chromosome 4 in MCF-7 AdVp3000 and MCF-7 MX, while S1-M1-80 contained only a simple reciprocal translocation. The parental cell lines had no chromosome 4 rearrangements and no copy number gain or amplification of chromosome 4. Spectral karyotyping (SKY) analysis revealed a balanced translocation, t(4;17)(q21-q22;p13) in S1-M1-80 and multiple clonal translocations involving chromosome 4 in MCF-7 AdVp3000 and MCF-7 MX. A novel cDNA, designated MXR, which encodes an ABC half-transporter and is highly overexpressed in the three sublines, was localized to chromosome 4 by somatic cell hybrid analysis. Southern blot analysis demonstrated amplification of the MXR gene in MCF-7 AdVp3000 and MCF-7 MX, but not in S1-M1-80. FISH studies with a BAC probe for MXR localized the gene to 4q21-22 in the normal chromosome 4 and revealed in both MCF-7 AdVp3000 and MCF-7 MX amplification of MXR at one translocation juncture, shown by SKY to be t(4;5)(4qter-->4cen-->4q21-22::5q13-->5qter++ +) in MCF-7 AdVp3000 and t(6;4;6;3)(6pter-->6q15::4q21-q22::hsr::6q?::3q?27-->+ ++3qter) in MCF MX; neither of the breakpoints in the partner chromosomes showed amplification by CGH. The data are consistent with the hypothesis of a transporter, presumably that encoded by the MXR gene, mediating mitoxantrone resistance. The MXR gene encodes a half-transporter and the absence of cytogenetic evidence of coamplification of other regions suggests that a partner may not be overexpressed, and instead the MXR half-transporter homodimerizes to mediate drug transport. Genes Chromosomes Cancer 27:110-116, 2000. Published 2000 Wiley-Liss, Inc.

Intrinsic drug resistance in primary and metastatic renal cell carcinoma

Much remains to be learned about drug resistance in the biology of RCC and its metastases. We measured MDR-1/P-glycoprotein expression in 19 tumor samples from patients with metastatic RCC by RNase protection and quantitative PCR assays. The median level of the 16 tumor metastases was 4.9 (range: 0.10 to 156.2) relative to the level of 10 assigned to a reference cell line, SW620, which has been characterized as expressing a minimum level of MDR-1. Since these levels were lower than expected for RCC, we asked whether the metastases possessed a phenotype different from primary RCC and examined MDR-1 expression in 5 paired cell lines derived from primary and metastatic RCC. In 8/10 lines, MDR-1 expression was >10. Relative to the level in the primary line, MDR-1 expression was decreased (3 to 50-fold) in 3 metastatic lines, was increased in 1, and unchanged in 1. MRP mRNA expression was lower in the metastatic lines while EGFR expression was variable. IC50 values for 6 compounds (including 4 standard agents and one new Phase 1 agent) were determined for the paired lines. Rhodamine and calcein efflux assays were performed as measures of P-glycoprotein and MRP function. Rhodamine efflux correlated with MDR-1 mRNA expression (r = 0.87) and with the IC50s (r = 0.60) for paclitaxel in the paired cell lines. In contrast, calcein efflux did not correlate with MRP expression. Lastly, MDR-1 expression correlated with cytokeratin 8 (CK8) protein levels, a measure of cellular differentiation. In sum, these data suggest renal cell carcinoma (RCC) metastases have altered MDR-1 expression potentially due to altered differentiation relative to the primary tumor. Thus, the drug resistance phenotype of primary RCC tumors may not reflect that of their metastases.

Molecular cloning of cDNAs which are highly overexpressed in mitoxantrone-resistant cells: demonstration of homology to ABC transport genes

Reports of multiple distinct mitoxantrone-resistant sublines without overexpression of P-glycoprotein or the multidrug-resistance associated protein have raised the possibility of the existence of another major transporter conferring drug resistance. In the present study, a cDNA library from mitoxantrone-resistant S1-M1-80 human colon carcinoma cells was screened by differential hybridization. Two cDNAs of different lengths were isolated and designated MXR1 and MXR2. Sequencing revealed a high degree of homology for the cDNAs with Expressed Sequence Tag sequences previously identified as belonging to an ATP binding cassette transporter. Homology to the Drosophila white gene and its homologues was found for the predicted amino acid sequence. Using either cDNA as a probe in a Northern analysis demonstrated high levels of expression in the S1-M1-80 cells and in the human breast cancer subline, MCF-7 AdVp3000. Levels were lower in earlier steps of selection, and in partial revertants. The gene is amplified 10-12-fold in the MCF-7 AdVp3000 cells, but not in the S1-M1-80 cells These studies are consistent with the identification of a new ATP binding cassette transporter, which is overexpressed in mitoxantrone-resistant cells.