IL-18, a product of choriodecidual cells, increases during premature rupture of membranes but fails to turn on the Fas-FasL-mediated apoptosis pathway

Problem: IL-18 is a novel cytokine, which promotes inflammation and apoptosis. This study examines its expression pattern, site of production, and levels in the amniotic fluid (AF) during pregnancy complications such as preterm labor and preterm premature rupture of membranes (pPROM). The ability of IL-18 to induce the Fas–Fas ligand (FasL)/caspase-mediated apoptotic pathway is also studied.Methods: Amniochorion collected at term was placed in an organ explant system. IL-18 mRNA expression was studied by RT-PCR. IL-18 mRNA and peptide were localized by in situ hybridization and immunohistochemistry. IL-18 in the AF of women with pPROM, with preterm labor with no rupture of membranes, and at term was measured using ELISA. Multiplex PCR was used to study the expression pattern of proapoptotic genes such as Fas, FasL, caspase 8, and Fas-associated death domain (FADD). ELISA was also used to measure the release of soluble Fas from IL-18-stimulated amniochorion in culture media.Results: IL-18 is a constitutively expressed gene in human chorion and decidua but not in human amnion and increases in the AF of women with pPROM [2.9 ± 3.3 ng/ml (SD)] compared to women with preterm labor (1.1 ± 0.67 ng/ml; P < 0.05) and term (0.9 ± 0.73 ng/ml; P < 0.05). IL-18 induces Fas expression, whereas FADD is a constitutively expressed gene in human fetal membranes. IL-18 failed to induce FasL or caspase 8 expressions. Soluble Fas release from amniochorion was increased after IL-18 stimulation.Conclusion: Chorion and decidua are a source of IL-18, whose concentrations are increased in the AF during pPROM. IL-18 induced Fas expression in amniochorion; however, it failed to turn on other genes in the Fas–FasL apoptosis pathway including FasL and caspase 8.     

MMP/TIMP imbalance in amniotic fluid during PROM: an indirect support for endogenous pathway to membrane rupture

OBJECTIVE: We theorize that excessive degradation of the fetal membrane extracellular matrix (ECM) by specific matrix metalloproteinases (MMPs) results in preterm premature rupture of the membranes (PROM). Active, inhibitor free MMP2 and 9 (gelatinase A and B respectively) can degrade the amniochorion basement membrane Type IV collagen to initiate rupture. This study examines the levels of the gelatinases and their natural inhibitors (tissue inhibitor of matrix metalloproteinases-TIMPs) in the amniotic fluid during PROM, preterm labor (PTL) and at term. METHODS: A total of 51 AF samples were collected from the following groups of patients. Group 1: Women with PTL and no ROM (n = 16) Group 2: Women with PROM (n = 16) irrespective of labor status Group 3: Women at term with intact membranes undergoing cesarean delivery irrespective of labor status (n = 19). ELISA was used to assay MMP2, MMP9, TIMP1 and TIMP2 levels in the amniotic fluid. The active, TIMP free levels of MMP2 were quantitated by zymography followed by computerized densitometry. Active MMP9 was measured using a bioassay that specifically detects MMP9 activity. Statistical analysis was performed by Tukey-Kramer multiple comparison method. RESULTS: PROM is associated with increased MMP2 levels (mean 2125 ng/ml;) when compared with term (mean 1455 ng/ml; p < 0.01) or PTL where a non significant increase was seen (mean 1862 ng/ml; p = ns). MMP9 levels were higher in PROM (mean 15.03 ng/ml) than at term (mean 1.14 ng/ml; p < 0.001) or PTL (mean 3.75 ng/ml; p < 0.01). TIMP1 levels were slightly increased during PROM (mean 3143 ng/ml) compared to term (mean 1892 ng/ml; p < 0.05) pr PTL where a non significant change was seen (mean 2406 ng/ml; p = ns). TIMP2 levels were decreased in PROM (mean 98 ng/ml) compared with term (mean 176 ng/ml; p < 0.05) and PTL (mean 236 ng/ml; p < 0.001). Active, TIMP free MMP2 levels were increased during PROM (mean 233 pg/ml) compared to those at term (mean 132 pg/ml; p < 0.05) or PTL (mean 132 pg/ml; p < 0.05). Active forms of MMP9 were seen only during PROM (mean 632 pg/ml). CONCLUSION: Active, TIMP free forms of MMP2 and 9 are increased in the amniotic fluid of women with PROM. These MMPs can degrade the amniochorion basement membranes and other ECM components resulting in PROM.     

Distinct molecular events suggest different pathways for preterm labor and premature rupture of membranes

OBJECTIVE: On a clinical level, the etiologies associated with premature rupture of the membranes and preterm labor are virtually identical, though these conditions end in distinctly different events. This study was designed to determine differences between preterm labor and preterm premature rupture of membranes by using molecular markers of extracellular matrix degradation and apoptosis. STUDY DESIGN: Amniochorion and amniotic fluid samples were collected from gestational age-matched groups of women undergoing cesarean delivery before term. Samples were collected from 2 groups of women, women with premature rupture of membranes and women with preterm labor with no rupture of membranes. Changes in the expression pattern of messenger ribonucleic acid for matrix metalloproteinases (MMP), tissue inhibitor of metalloproteinases (TIMP), and pro-apoptotic (p53 and Bax) and anti-apoptotic (Bcl-2) proteins were identified by quantitative polymerase chain reaction. Enzyme-linked immunosorbent assay was used to determine the levels of these proteins in the amniotic fluid. Multiplex polymerase chain reaction was performed to study the expression of Fas-Fas ligand-associated pro-apoptotic genes. Unpaired nonparametric, 2-tailed Mann-Whitney U test was used to determine statistical significance of quantitative polymerase chain reaction and enzyme-linked immunosorbent assay (P <.05 was considered significant). RESULTS: Quantitative polymerase chain reaction results demonstrated an increased mRNA expression for MMP2, MMP9, and MT1-MMP and a decreased expression for TIMP2 in prematurely ruptured membranes compared with preterm labor membranes. Enzyme-linked immunosorbent assay documented increases in the amniotic fluid concentrations of immunoreactive and bioactive MMP2 and MMP9 and immunoreactive MMP3 and a decreased TIMP2 concentration in fluids obtained from the premature rupture of membranes group compared with the preterm labor group. The pro-apoptotic genes p53 and bax were up-regulated in premature rupture of membranes when compared with preterm labor. Anti-apoptotic gene (Bcl-2 ) expression was increased in preterm labor membranes compared with prematurely ruptured membranes. Interleukin-18 (a pro-apoptotic cytokine) was increased in the amniotic fluid during premature rupture of membranes compared with preterm labor. Prematurely ruptured membranes also demonstrated fragmented deoxyribonucleic acid and expression of Fas and caspase 8 (apoptosis initiator), which were all absent in preterm labor membranes. CONCLUSIONS: We have begun to delineate 2 divergent molecular pathways for premature rupture of membranes and preterm labor. Most likely, this is the beginning of the identification of differences that will become evident with the use of molecular biology.     

Evaluation of the expression and enzyme activity of matrix metalloproteinase-7 in fetal membranes during premature rupture of membranes at term in humans

Amnion, chorion, and decidua were separated from fetal membranes at term from women with no labor (cesarean delivery [CS], n = 10), labor (normal delivery, n = 10), and labor during premature rupture of membranes (PROM; n = 8) for evaluation of matrix metalloproteinase (MMP)-7. The expression of pro-MMP-7 was immunohistochemically demonstrated in amnion, chorion, and decidua. Interestingly, however, Western blotting revealed that pro-MMP-7 and MMP-7 expression was the lowest in amnion from PROM, whereas it was the highest in chorion and decidua from PROM. Importantly, the enzymatic activity of MMP-7 determined with an MMP-7-specific substrate was higher in amnion from PROM than that from CS. Moreover, the tissue inhibitor of metalloproteinase (TIMP)-1 level was lower in amnion from PROM than that from CS. Thus, MMP-7 is expressed in fetal membranes (amnion, chorion, and decidua), and its activity is increased in amnion of PROM at term, accompanied with the reduced level of TIMP-1, which may suggest the possible involvement of MMP-7 in PROM.     

Pigment epithelial-derived factor in human fetal membranes

Objective: Our main objective was to document, pigment epithelial-derived factor (PEDF), a secreted serine protease inhibitor with anti-angiogenic, anti-inflammatory, and anti-oxidant properties, expression in human fetal membranes from preterm prelabor rupture of the membranes (pPROM) and in in vitro cultures stimulated with cigarette smoke extract (CSE) or lipopolysaccharides (LPS), two major risk factors for pPROM (behavioral and bacterial, respectively).

Method: We documented PEDF mRNA expression in clinical samples of fetal membranes from patients with pPROM using quantitative RT-PCR. Also, mRNA and protein levels were documented in fetal membranes (from normal term cesarean sections [not in labor]) in an organ explant system stimulated with CSE or lipopolysaccharide (LPS). Immunohistochemistry (IHC) was used to localize PEDF in fetal membranes.

Results: We report no changes in PEDF mRNA expression in pPROM compared to term births (p?=?.59) or after treatment with CSE or LPS. However, by adding sulforaphane the PEDF mRNA expression increased significantly p?Conclusions: PEDF, a product of fetal membrane cells, is unaltered in pPROM or after exposure to risk factors of pPROM. The antioxidant stimulating substance sulforaphane contribute to an increase in PEDF mRNA in fetal membranes.     

The role of extracellular inducer of matrix metalloproteinases in premature rupture of membranes

Objective: To investigate the role of matrix metalloproteinases (MMP-2, MMP-9) and their inducer (CD147) in premature rupture of membranes (PROM) at term labor.

Methods: In a cross-sectional study, 24 women aged 19–39, with 37–40-week pregnancy, and no clinical and histological signs of chorioamnionitis, were divided into two groups with and without PROM. The histological and immunohistochemical study of the fetal membranes was performed with polyclonal rabbit antibodies to MMP-2/MMP-9 and monoclonal rabbit antibodies to CD147.

Results: The analysis of MMP revealed the increase of MMP-9 expression in the amniotic epithelium during premature membrane rupture both in rupture area, and beyond it, and increased MMR-2 expression in the mesodermal cells. We also found high level of CD147 in the amniotic epithelium in PROM group. The above-mentioned changes were found in all areas of fetal membranes, regardless of the rupture localization.

Conclusions: The study results demonstrate the increased expression of MMR-2 and MMR-9, which regulate the catabolism of fetal membrane extracellular matrix proteins, in amniotic membranes of women with PROM at term labor. The increased expression of CD147 may be one of the mechanisms triggering PROM in the absence of infection.     

Thrombin-dependent regulation of matrix metalloproteinase (MMP)-9 levels in human fetal membranes*

Objective.?Amniochorion matrix metalloproteinase (MMP)-9 levels increase during labor, reaching a maximum in patients with preterm premature rupture of membranes (PPROM). Bleeding is a major risk factor for PPROM. Since such hemorrhage into the tissue factor-enriched decidua induces intense thrombin formation, we determined whether thrombin stimulates MMP levels in amniochorionic membranes.

Study design.?Fetal membrane (amniochorion) cultures were maintained in media with and without thrombin, lipopolysaccharide (LPS), thrombin receptor agonist peptide (TRAP)-14, and the anti-inflammatory steroid, dexamethasone (DEX). Concentrations of MMP-9, MMP-1, and tissue inhibitor of metalloproteinase (TIMP)-1 in culture media were measured by ELISA and normalized to total cell protein.

Results.?The presence of thrombin induced MMP-9 levels. TRAP-14, a thrombin receptor agonist, also significantly increased MMP-9 levels, suggesting that thrombin-induced changes in MMP-9 expression were mediated through the thrombin receptor. Conversely, levels of MMP-1 and TIMP-1 were not affected by thrombin treatment, indicative of specificity of its action. The presence of LPS increased the concentration of MMP-9 and MMP-1. In contrast, DEX treatment significantly reduced MMP-9 levels.

Conclusion.?Our findings clearly demonstrated that thrombin treatment selectively increased the concentration of MMP-9 in culture media of amniochorionic membranes. Our results provide a potential mechanism through which alterations in hemostasis promote PPROM through thrombin-dependent stimulation of MMP-9.     

TNF-alpha promotes caspase activation and apoptosis in human fetal membranes

Purpose: Increased amniotic fluid tumor necrosis factor (TNF) is a marker of infection when associated with preterm labor and preterm premature rupture of the amniochorionic membranes (PROM). We have noted increased apoptosis in membranes derived from women with PROM. This study examines the role of TNF in promoting fetal membrane apoptosis. Methods: Amniochorion (n = 8), collected at the time of elective repeat cesarean section prior to labor from normal term gestation, were placed in an organ explant system. After 48 h in culture, the membranes were stimulated with recombinant TNF- (20 ng/mL) for 24 h. Tissue frozen after stimulation was subjected to RT-PCR to study the expression of TNF-induced caspase genes. ELISA assayed the levels of proapoptotic p53 in tissues and cell death related nuclear matrix protein (NMP) in tissue culture supernatants. The activity of caspases in tissue homogenates was measured using substrates specific for caspase 2, 3, 6, 8, and 9. Results were analyzed by using the Wilcoxon nonparametric test for paired samples. A p < 0.05 was considered significant. Results: RT-PCR showed induction of caspases 2, 8, and 9 (caspase cascade initiators) in human fetal membranes after TNF stimulation. Caspases 3 and 6 (effector caspases) expression was constitutive in both TNF stimulated- and control membranes. Caspases, 2, 3, 8, and 9 activity was significantly higher in TNF-stimulated tissues compared with control, whereas, no significant change in caspase 6 activity was noticed. TNF-stimulated tissues released increased levels of NMP (24.03 U/mL) compared with control (13.5U/mL) (p = 0.03). TNF also increased p53 levels in the tissues (0.05 ng/mL) compared with control cultures (0.03 ng/mL; p = 0.02). Conclusions: TNF increases proapoptotic p53 levels and caspase activities in fetal membranes. Increased NMP reflects cell death.     

A role for the 72 kDa gelatinase (MMP-2) and its inhibitor (TIMP-2) in human parturition, premature rupture of membranes and intraamniotic infection

OBJECTIVE: Degradation of the extracellular matrix in fetal membranes has been implicated in the process of parturition and rupture of membranes. Matrix metalloproteinases (MMPs) are enzymes capable of degrading extracellular matrix including collagen. Tissue inhibitors of matrix metalloproteinases (TIMPs) inhibit the activity of MMPs by covalently binding to the enzymes. MMP-2 degrades Type IV collagen and TIMP-2 is its specific inhibitor. The objective of this study was to determine if human parturition, rupture of membranes (term and preterm) and microbial invasion of the amniotic cavity (MIAC) are associated with changes in the concentrations of MMP-2 and TIMP-2 in amniotic fluid. STUDY DESIGN: A cross-sectional study was conducted with women in the following categories: 1) term with intact membranes, in labor and not in labor; 2) preterm labor and intact membranes who delivered at term, who delivered preterm and preterm labor with MIAC; 3) preterm premature rupture of membranes (PROM) with and without infection; 4) term and preterm PROM not in labor; and 5) midtrimester. MMP-2 and TIMP-2 concentrations in amniotic fluid were determined using sensitive and specific immunoassays. RESULTS: The concentration of TIMP-2 increased with advancing gestational age (r = 0.6, p < 0.001). No correlation was found between MMP-2 concentrations and gestational age. Human parturition and rupture of membranes (term and preterm) and in patients with intact membranes were not associated with changes in the amniotic fluid MMP-2 concentrations. In contrast, 1) patients with spontaneous labor (term and preterm) had significantly lower median concentrations of TIMP-2 compared to those not in labor (p < 0.05 for both); 2) MIAC in women with preterm labor and preterm PROM was associated with a significant decrease in amniotic fluid TIMP-2 concentrations (p < 0.04 for both comparisons); 3) Rupture of the membranes (term and preterm) was also associated with a significant decrease in the amniotic fluid TIMP-2 concentrations (p < 0.05 and p < 0.03, respectively). CONCLUSIONS: Human parturition (preterm and term), rupture of fetal membranes (term and preterm) and intraamniotic infection are associated with a significant decrease in amniotic fluid TIMP-2 concentrations.     

High bisphenol A (BPA) concentration in the maternal,but not fetal,compartment increases the risk of spontaneous preterm delivery

Objective: The objective of this study is to determine if BPA exposure, as measured by maternal plasma (MP) and amniotic fluid (AF) BPA concentrations is associated with an increased risk of spontaneous preterm birth (PTB) and preterm premature rupture of membranes (pPROM).

Methods: In this nested case–control study, MP samples from women in term labor (n?=?30), preterm labor that ended with preterm delivery (n?=?25), or who had pPROM (n?=?30) and amniotic fluid samples from term labor (n=?45), preterm labor (n?=?60), and pPROM (n?=?35) were assayed for BPA by enzyme immunoassay.

Results: BPA was detectible in 100% of MP and AF samples. Women with MP BPA concentrations in the fourth quartile were at increased risk of PTB (cOR?=?4.12, 95% CI?=?1.32–12.87; aOR?=?4.78, 95% CI?=?1.14–20) but not pPROM. High (fourth quartile) AF BPA values also tended to increase the risk of pPROM (cOR?=?2.47, 95% CI?=?0.96–6.37) but results were not statistically significant.

Conclusions: Increased BPA concentration is associated with an increased risk for PTB or pPROM depending on the maternal–fetal compartment(s) affected. High MP plasma BPA concentrations are associated with PTB with intact membranes but high AF BPA concentrations may weakly be associated with pPROM.     

Changes in matrix metalloproteinase (MMP)-2 and MMP-9 in the fetal amnion and chorion during gestation and at term and preterm labor

Increased matrix metalloproteinase (MMP)-9 proteolytic activity is associated with term birth, preterm birth and premature rupture of membranes. However, most studies show no changes with MMP-2, which binds tightly to cell and matrix proteins. We hypothesized better protein extraction would reveal new MMP patterns. Human amnion and chorion were collected from 25 patients at preterm or term, extracted with 2% SDS (a high concentration), and the MMP protein levels and pro-enzyme activities were determined by Western immunoblotting and zymography. MMP-2 protein and MMP-2 and -9 pro-enzyme activities in the amnion increased significantly (p<0.05) with labor at term, and were higher than at preterm labor (p<0.05), when extracted with high SDS concentration. There were no changes in chorion MMPs under any condition. These associations suggest MMP-2 may be another regulator of membrane rupture and other labor-associated mechanisms at term parturition, and its role(s) should be examined further.     

Programmed cell death (apoptosis) in placentas from normal pregnancy and pregnancy complicated by term (t) and preterm (p) premature rupture of membranes (PROM)

Objective: The aim of this study was to determine the apoptotic index using three different apoptotic markers: terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL); M30 cytoDEATH antibody and fluorescein isothiocyanate (FTIC)-labeled annexin-V in the placenta and membranes from normal pregnancy and pregnancy complicated by premature rupture of membranes (PROM). Study design: Placentas from 16 pregnancies (22–40 weeks’ gestation) and 13 pregnancies complicated by pPROM and tPROM were collected at delivery. Maternal and gestational age, mode of delivery, gravidity and parity, fetal birthweight, Apgar scores, presence of histologic chorioamnionitis, interval between membrane rupture and delivery were recorded among PPROM and tPROM cases. Results: Only M30 cytoDEATH antibody (P=0.02) and TUNEL test (P=0.04) on fetal membranes gave statistically significantly higher levels in cases with premature rupture of membranes. The presence of histologic chorioamnionitis had no significant impact on apoptotic markers in PROM placentas. Preterm deliveries following the rupture of membranes had higher median AI values detected by M30_M antibody, compared to those cases delivered without PROM (P=0.03). Conclusion: High apoptotic nuclei counts were found in fetal membranes of pPROM.     

The role of matrix degrading enzymes and apoptosis in rupture of membranes

Prematurity is the third leading cause of perinatal death, and preterm premature rupture of the membranes (pPROM) is associated with approximately 20-50% of all preterm births. The etiologic factors described for pPROM and preterm labor (PTL) are the same, although the clinical presentation (pPROM vs PTL) differs among patients. The reason for this disparity is unknown and poses a therapeutic dilemma. Several etiologic factors have been described for PTL and pPROM. PTL and pPROM are associated with overwhelming host inflammatory response. Many of these pro-inflammatory factors (inflammatory cytokine release) are common in both conditions; however, the clinical presentation differs. The objective of this review is to explain the differential expression pattern of matrix metalloproteinases (MMPs) and pro-apoptotic elements in human fetal membranes in pPROM and PTL and how they interact to present different clinical outcomes during pregnancy.     

Evidence in support of a role for anti-angiogenic factors in preterm prelabor rupture of membranes

Objective.?Vaginal bleeding, placental abruption, and defective placentation are frequently observed in patients with preterm prelabor rupture of membranes (PROM). Recently, a role of vascular endothelial growth factor (VEGF) and its receptor, VEGF receptor (VEGFR)- 1 has been implicated in the mechanisms of membrane rupture. The purpose of this study was to determine whether the soluble form of VEGFR-1 and -2 concentrations in amniotic fluid (AF) change with preterm PROM, intra-amniotic infection/inflammation (IAI), or parturition.

Study design.?This cross-sectional study included 544 patients in the following groups: (1) midtrimester (MT) (n?=?48); (2) preterm labor (PTL) leading to term delivery (n?=?143); (3) PTL resulting in preterm delivery with (n?=?72) and without IAI (n?=?100); (4) preterm PROM with (n?=?46) and without IAI (n?=?42); (5) term in labor (n?=?48); and (6) term not in labor (n?=?45). The concentrations of sVEGFR-1 and sVEGFR-2 were determined by ELISA. Non-parametric statistics and logistic regression analysis were applied.

Results.?(1) Preterm PROM (with and without IAI) had a lower median AF concentration of sVEGFR-1 than patients with PTL who delivered at term (p?<?0.001 for each comparison); (2) A decrease in AFsVEGFR-1 concentrations per each quartile was associated with PROM after adjusting for confounders (OR 1.8; 95%CI 1.4–2.3); (3) IAI, regardless of the membrane status, was not associated with a change in the median AF concentrations of sVEGFR-1 and sVEGFR-2 (p?>?0.05 for each comparison); and (4) Spontaneous term and PTL did not change the median sVEGFR-1 and sVEGFR-2 concentrations (p?>?0.05 for each comparison).

Conclusion.?(1) This is the first evidence that preterm PROM is associated with a lower AF concentration of sVEGFR-1 than patients with PTL intact membranes. These findings cannot be attributed to gestational age, labor, or IAI; and (2) AF concentrations of sVEGFR-2 did not change with preterm PROM, IAI, or labor at term and preterm.     

Ⅲ型胶原及CTGF在胎膜早破发病机制中的作用

目的探讨Ⅲ型胶原、结缔组织生长因子（CTGF）在人胎膜组织中的表达及在胎膜早破发病机制中的作用。方法38例胎膜早破孕妇为胎膜早破组，其中未足月胎膜早破组（pPROM组）18例，足月胎膜早破组（tPROM组）20例；与胎膜早破组孕周相对应的非胎膜早破孕妇作为对照组，早产对照组18例，足月对照组20例。应用免疫组化及图像分析法检测胎膜Ⅲ型胶原、CTGF表达水平，以阳性区平均灰度值为检测依据。将各组孕妇胎膜Ⅲ型胶原、CTGF测定结果进行直线相关分析。结果①四组胎膜中均存在不同程度的Ⅲ型胶原、CTGF的表达；②pPROM组Ⅲ型胶原（88．81±5．25）、CTGF水平（85．45±6．91）均低于早产对照组（95．99±8．41，90．30±5．74），差异有统计学意义（P〈0．01，P〈0．05）；tPROM组Ⅲ型胶原（94．53±6．43）、CTGF（88．15±4．93）均低于足月对照组（100．80±9．77，93．20±5．33），（P〈0．05）；pPROM组Ⅲ型胶原（88．81±5．25）表达低于tPROM组（94．53±6．43），两者比较差异有统计学意义（P〈0．01）；pPROM组CT—GF灰度值（85．45±6．91）表达低于tPROM组（88．15±4．93）．但无统计学差异（P〉0．05）；③Ⅲ型胶原、CTGF水平在pPROM组中的表达呈正相关性，r=0．830（P〈0．01），而tPROM组中两者则无相关性。结论pPROM组与tPROM组中存在Ⅲ型胶原与CTGF的低表达。tPROM的发生可能与胎膜的退行性变有关，而pPROM的发生与胎膜本身结构病变密切相关。     

Cx43、Bax和Bcl-2在胎膜早破患者胎膜组织中的表达及意义

目的检测间隙连接蛋白43（Cx43）在胎膜早破患者胎膜组织中的表达,分析其与凋亡相关蛋白Bax、Bcl-2表达的相关性,探讨三者与胎膜早破发生的关系。方法随机选择本院剖宫产分娩的孕32-42周胎膜早破孕妇30例（胎膜早破组）,其中未足月胎膜早破（pPROM）15例,足月胎膜早破（tPROM）15例;无胎膜早破孕妇30例（对照组）。采用免疫组化法（PV法）检测Cx43、Bax和Bcl-2的表达并进行图像分析。结果①各组胎膜组织中均可见Cx43、Bax、Bcl-2不同程度的表达。②tPROM组Cx43、Bcl-2的表达明显低于对照组（P〈0．01）,而Bax的表达高于对照组,差异均有显著性（P〈0．05）。tPROM组Cx43的表达高于pPROM组,差异有显著性（P〈0．01）;而Bcl-2、Bax在两组中比较,差异无显著性（P〉0．05）。③PROM组人工胎膜破口附近Cx43、Bcl-2的表达低于非人工胎膜破口附近,Bax的表达则相反,两组比较,差异有显著性（均P〈0．01）。④PROM组Cx43的表达水平与Bax呈负相关（r=-0．309,P〈0．05）。结论胎膜组织中Cx43的低表达及细胞的过度凋亡可能对胎膜早破的发生起一定的促进作用。     

Gene expression of adhesion molecules and matrix metalloproteinases in endometriosis

Various types of cell adhesion molecules and matrix metalloproteinases (MMPs) seem to play an important role in the invasion process of endometriosis; however, limited investigation has focused on their gene expression in human peritoneal endometriotic lesions. A total of 63 endometriotic tissues were surgically obtained from 35 women with endometriosis, which included 43 pigmented and 20 non-pigmented lesions. Gene expression levels of E-cadherin, α- and β-catenin, MMP-2, MMP-9 and membrane-type 1 (MT1)-MMP in these endometriotic lesions were compared with those in normal eutopic endometrium obtained from 12 women without endometriosis. MMP-2, MMP-9 and MT1-MMP mRNA expression in pigmented lesions was significantly higher than that in normal endometrium (p < 0.05), whereas E-cadherin, α- and β-catenin mRNA expression was not suppressed in endometriotic lesions. There was a close correlation between MMP-2 or MT1-MMP and E-cadherin, α- or β-catenin gene expression in 63 endometriotic tissues examined (p < 0.01). Immunohistochemical expression of E-cadherin, α- and β-catenin in glandular epithelial cells was positive not only for all of seven cases with normal eutopic endometrium but also for 9 of 11 with ovarian endometriosis. MMP expression in ectopic endometrium was much greater than that in eutopic endometrium. These results suggest that endometriotic tissues expressing MMPs might be invasive and simultaneously possess cell-to-cell adhesion property in pelvic peritoneal foci.     

Are vaginal fluid procalcitonin levels useful for the prediction of subclinial infection in patients with preterm premature rupture of membranes?

AIM: To compare vaginal fluid procalcitonin concentrations in cases of preterm premature rupture of membranes (pPROM) and premature rupture of membranes (PROM) at term, and to determine whether the procalcitonin concentrations are of value in the diagnosis of pPROM cases suspected of subclinical intrauterine infection or in the prediction of the pPROM-to-delivery interval. METHODS: Forty-eight patients with pPROM and 30 with PROM at term were enrolled in this study. In pPROM group, analysis was conducted of procalcitonin concentrations with reference to serum leucocytosis, serum C-reactive protein levels and vaginal fluid culture, as well as to the presence/absence of neonatal congenital infection or histological chorioamnionitis. The outcomes of pPROM cases were also recorded with reference to pPROM-to-delivery interval. RESULTS: Procalcitonin levels in the pPROM group were significantly higher than in cases of amniorrhexis at term (1.50 vs 0.83 ng/mL; P < 0.001). In the pPROM group procalcitonin concentrations between the patients with and without positive laboratory indices of infection were comparable. Also, no significant correlation was observed between procalcitonin and leucocytosis (r = -0.14; P = 0.33) or C-reactive protein (r = -0.17; P = 0.24). Procalcitonin concentrations of patients who gave birth to newborns with infection were comparable to those in women whose newborns were healthy. In patients with histological chorioamnionitis, procalcitonin concentrations were comparable to those without inflammatory changes. CONCLUSION: These findings suggest that the value of vaginal fluid procalcitonin determinations is unsatisfactory in the diagnostics of pPROM cases suspected of subclinical intrauterine infection, as well as for the prediction of pPROM-to-delivery interval, newborn's congenital infection or histological chorioamnionitis.