Biomedical subjects

Karina Richani

Publications and source records attributed to Karina Richani.

9 recordsLinked to original sources

PubMed2006

Genetic origin and proportion of basal plate surface-lining cells in normal and abnormal pregnancies.

The human placenta is a transient organ, the villous surface of which is in direct contact with the maternal circulation during pregnancy. Thus, the syncytiotrophoblast and the basal plate-lining cells are considered continuous with the endothelial layer of the maternal vasculature. Two types of cells are found on the surface of the basal plate: trophoblasts (of fetal origin) and endothelial cells of putative maternal origin. Histologic abnormalities have been described in the basal plate of the placenta obtained from patients with preeclampsia and intrauterine growth restriction. Moreover, endothelial cell dysfunction and intravascular inflammation are key features of preeclampsia. The objectives of this study were to: (1) determine the origin of the endothelial cells located in the basal plate surface of the placenta (from male fetuses); and (2) analyze the relative proportion of the intervillous surface of the basal plate occupied by trophoblasts and endothelial cells. Immunohistochemistry and morphometry were performed in placentas from women in the following clinical groups: (1) normal-term pregnancies (n = 15); (2) severe preeclampsia at term (n = 15); (3) small-for-gestational-age (SGA) neonates delivered at term (n = 15); (4) preterm deliveries (<37 weeks) without inflammation (n = 5); and (5) preterm preeclampsia (n = 5). Laser capture microdissection and polymerase chain reaction were used to determine the allelic pattern of the amelogenin gene of the endothelial cells on the intervillous surface of the basal plate. Our results showed that: (1) the endothelial cells lining the basal plate in placentas of male fetuses were uniformly of maternal origin; and (2) in placentas from uncomplicated pregnancies, the median proportion of trophoblasts and endothelial cells covering the surface of the basal plate were 27.7% and 46.5%, respectively. The remaining area of the intervillous surface of the basal plate was composed of fibrin and anchoring villi. Of interest, placentas from women who delivered an SGA neonate had a higher proportion of trophoblasts and a lower proportion of endothelial cells lining the basal plate than those from normal pregnancies (P < .05). The same tendency was observed in placentas from patients with preeclampsia. This study demonstrates that endothelial cells of maternal origin cover the intervillous surface of the basal plate of the placenta, along with trophoblasts of fetal origin. The proportion of this surface lined by trophoblasts is greater in placentas from SGA and preeclampsia than in normal pregnancy. We propose that this change reflects a compensatory mechanism whereby the basal plate surface covered by injured endothelial cells is replaced by trophoblasts or results from a failure of trophoblastic involution in abnormal pregnancies. Our observations also suggest that the lining of the basal plate can provide information about the pathology of endothelial cells in complications of pregnancy.

Adolescent↗

PubMed2006

Fetal macrophages are not present in the myometrium of women with labor at term.

OBJECTIVE: The basic mechanisms responsible for human parturition remain to be elucidated. The influx of fetal leukocytes into the myometrium has been recently proposed to be a crucial event in the onset of murine parturition. Surfactant protein-A has been implicated in the initiation of labor. In mice, it is thought that surfactant protein-A induces migration and subsequent activation of amniotic fluid macrophages of fetal origin, which then invades the myometrium. The present study was conducted to determine whether fetal macrophages invade the myometrium of women in labor. STUDY DESIGN: Placental bed biopsy specimens were obtained from patients in labor who delivered male neonates at term (n = 7). Myometrial sections of postpartum hysterectomy specimens obtained from women who delivered of male neonates (n = 3) were also analyzed. Formalin-fixed, paraffin-embedded sections were immunostained for CD68 or CD14 (which are markers for macrophages); immunoreactive myometrial macrophages were specifically procured by laser capture microdissection. Sex typing was done by polymerase chain reaction for the amelogenin gene with genomic DNA that was isolated from the macrophages. Chromogenic in situ hybridization with a Y chromosome-specific probe was also performed on paraffin-embedded histologic sections. RESULTS: Amelogenin allelotypes of the macrophages were consistent with female alleles in all cases that were tested, indicating a maternal origin. Chromogenic in situ hybridization demonstrated the absence of Y chromosome-positive mononuclear cells in the myometrium in all cases. CONCLUSION: These observations, from a limited number of cases, suggest that migration of fetal macrophages from the amniotic cavity or the chorioamniotic membranes into the myometrium does not occur during human labor. The trafficking of fetal macrophages in labor seems to be different in humans and mice.

Female↗

PubMed2006

A rapid MMP-8 bedside test for the detection of intra-amniotic inflammation identifies patients at risk for imminent preterm delivery.

OBJECTIVE: Matrix metalloproteinase-8 (MMP-8) is an enzyme that is released during neutrophil activation. MMP-8 amniotic fluid concentrations are elevated not only in patients with intra-amniotic infection, but also in patients with negative amniotic fluid cultures who deliver preterm neonates. The objective of this study was to determine whether the results of a rapid MMP-8 bedside test predict imminent preterm delivery. This test can be performed in 15 minutes and without laboratory equipment. STUDY DESIGN: Amniotic fluid was retrieved from 331 patients admitted with increased preterm uterine contractions and intact membranes who met the inclusion criteria. Amniotic fluid was processed for microbial cultures, Gram stain, glucose concentration, and white blood cell count. Amniotic fluid samples were stored, and the MMP-8 rapid test was performed after delivery. End points included spontaneous preterm delivery within 48 hours, 7 days, and 14 days. Diagnostic indices, predictive values, and likelihood ratios were calculated. RESULTS: The prevalence of spontaneous preterm delivery within 48 hours, 7 days, and 14 days was 11.6% (38/327), 20.2% (66/327), and 24.5% (80/327), respectively (4 patients with augmentation of labor were excluded). A positive MMP-8 rapid test had a positive predictive value of 70% (23/33) for the identification of patients who delivered spontaneously within 48 hours, and 94% (31/33) for patients who were delivered within 7 days and 14 days (likelihood ratios: 17.5 [95% CI, 9-33.9], 61.3 [95% CI, 15.1-250], and 50 [95% CI, 12-196], respectively). CONCLUSION: The MMP-8 rapid test can identify patients at risk for preterm delivery within 7 days and 14 days. Moreover, a positive MMP-8 rapid test result can identify patients with intra-amniotic infection/inflammation with a high sensitivity and specificity. This rapid test will give clinicians a fast and accurate assessment of the inflammatory status of the amniotic cavity and allow for better identification of patients at risk for impending preterm delivery.

Adult↗

PubMed2006

Tissue microarray: an effective high-throughput method to study the placenta for clinical and research purposes.

OBJECTIVE: Tissue microarray (TMA) technology allows simultaneous examination of the expression of many molecular markers (protein, mRNA, DNA, etc.) with high-throughput. The application of this technology, to date, has been largely confined to the study of cancer. Placental pathology poses unique challenges because of the size of the organ, its complex anatomy, as well as its histological heterogeneity. The objective of this study was to assess the feasibility and efficiency of TMAs for immunohistochemistry and in situ hybridization of placental tissues. STUDY DESIGN: TMAs were constructed using an automated tissue arrayer. Standard 0.6-mm or 1-mm microarray needles were used. Villous parenchyma, basal plate, and chorioamniotic membranes were targeted in each block. Five mum-thick TMA sections underwent immunohistochemical analysis of both cytoplasmic and nuclear antigens using a panel of antibodies against a variety of cytoplasmic [cytokeratin-7, vascular endothelial growth factor (VEGF), and protein Z], membranous (endoglin), and nuclear (c-fos and c-jun) antigens. mRNA in situ hybridization for surfactant protein A (SP-A) and chromogenic in situ hybridization for the Y chromosome (DYZ1) were also performed. RESULTS: Validation of TMA immunoreactivity demonstrated comparable results with corresponding whole sections. When a two-tiered scoring system (positive/negative) was employed, there was agreement between two and three cores and whole tissue sections (kappa>0.7). When a three-tiered scoring system (negative, weak-positive, or strong-positive) was used, the data from three cores showed the highest agreement with whole tissue sections (kappa >0.7). In situ hybridization experiments for mRNA and DNA were also successful in that the signals were readily detectable. Successful transfer from the donor block to the recipient block differed according to the anatomical compartment. The transfer efficiency of villous parenchyma, basal plate, and chorioamniotic membranes were 96.9% (875/903), 76.7% (115/150), and 75.4% (224/297), respectively. CONCLUSION: TMA is a practical and effective tool for high-throughput molecular analysis of the human placenta. Duplicate and triplicate cores offer agreement with whole tissue sections for two-category distinction immunostaining. TMA also affords relevant results from in situ hybridization experiments for mRNA and DNA. The major advantages are the conservation of tissues and reagents, simultaneous comparison of molecular markers in different anatomical compartments of the placenta, and reduction of experimental error.

Biomarkers↗

PubMed2006

A role of the anti-angiogenic factor sVEGFR-1 in the 'mirror syndrome' (Ballantyne's syndrome).

BACKGROUND: 'Mirror syndrome' (Ballantyne's syndrome) refers to the association of fetal hydrops with placentomegaly and severe maternal edema. Preeclampsia occurs in approximately 50% of these cases. Soluble vascular endothelial growth factor receptor-1 (sVEGFR-1), an anti-angiogenic factor, has been implicated in the pathophysiology of preeclampsia (PE). OBJECTIVE: The objective of this study was to determine if the maternal plasma concentration of sVEGFR-1 is elevated in patients with mirror syndrome. STUDY DESIGN: This case-control study included patients with uncomplicated pregnancies (n = 40) and those with mirror syndrome (n = 4) matched for gestational age. Mirror syndrome was defined as fetal hydrops and severe maternal edema. Maternal plasma sVEGFR-1 concentrations were determined using specific enzyme-linked immunosorbent assays. Immunohistochemistry of sVEGFR-1 on villous trophoblasts was also performed in samples from one patient with mirror syndrome and compared with those from a patient with spontaneous preterm delivery matched for gestational age. Non-parametric statistics were used for analysis (p < 0.05). RESULTS: (1) The median maternal plasma concentration of sVEGFR-1 was significantly higher in patients with mirror syndrome than in the control group (median: 3974 pg/mL, range: 3083-10 780 vs. median: 824 pg/mL, range: 260-4712, respectively; p < 0.001). (2) All patients with mirror syndrome had sVEGFR-1 concentrations above the 95th percentile for gestational age. Syncytiotrophoblast, especially syncytial knots, showed strong staining with antibodies against sVEGFR-1 in placental samples from the patient with mirror syndrome, but not in those from the patient with spontaneous preterm delivery. CONCLUSION: High maternal plasma concentrations of sVEGFR-1 were observed in mirror syndrome. We propose that this anti-angiogenic factor may participate in the pathophysiology of this syndrome. Thus, maternal plasma determination of sVEGFR-1 may help to identify the hydropic fetus that places the mother at risk for preeclampsia.

Adult↗

PubMed2005

Normal pregnancy is characterized by systemic activation of the complement system.

BACKGROUND: The complement system, a major component of innate immunity, has recently been implicated in the mechanisms of fetal loss and placental inflammation in the anti-phospholipid antibody syndrome. Inhibition of complement has been proposed as an absolute requirement for normal pregnancy. Yet, pregnancy is characterized by a generalized activation of the innate immune system. This study was conducted to determine whether or not normal pregnancy is associated with complement activation in the maternal circulation. METHODS: Anaphylatoxins (C3a, C4a and C5a) were determined in the plasma of normal pregnant (20-42 wks; n=134) and non-pregnant women (n=40). These complement split products (C3a, C4a and C5a) were measured using specific immunoassays. Non-parametric statistics were used for analysis. RESULTS: 1) The median plasma concentrations of C3a, C4a and C5a were significantly higher in normal pregnant women than in non-pregnant women (all p<0.001); 2) the concentration of C3a, C4a and C5a did not change with gestational age (p>0.05); and 3) the median plasma concentration of C3a had a positive correlation with the plasma C4a and C5a concentrations (r=0.36, p<0.001 and r=0.35, p<0.001, respectively). CONCLUSION: 1) Normal human pregnancy is associated with evidence of complement activation, as determined by higher concentrations of the anaphylatoxins C3a, C4a and C5a in the maternal circulation; and 2) we propose that physiologic activation of the complement system during pregnancy is a compensatory mechanism aimed at protecting the host against infection.

Adolescent↗

PubMed2005

Increased concentration of the complement split product C5a in acute pyelonephritis during pregnancy.

OBJECTIVE: Pregnant women with acute pyelonephritis develop acute respiratory distress syndrome (ARDS) more frequently than non-pregnant women. The reasons for this remain unknown. The complement system is a complex set of self-assembling proteins that have been implicated in the pathophysiology of ARDS and sepsis. The purpose of this study was to determine if activation of the complement system occurs in pregnant women with acute pyelonephritis. METHODS: A cross-sectional study was conducted to determine the plasma concentrations of C3a, C4a and C5a (i.e., complement split products) in pregnant patients with acute pyelonephritis (n=38) and normal pregnant women (n=38). The complement split products C3a, C4a and C5a were measured using ELISA. Data were analyzed using non-parametric statistics. RESULTS: 1) The median plasma concentration of C5a in pregnant patients with acute pyelonephritis was significantly higher than that in normal pregnant women (p<0.001); 2) there was no statistical difference in the median plasma concentration of C3a and C4a between the two groups (p>0.05); and 3) concentrations of C3a, C4a and C5a were not different among patients with acute pyelonephritis with and without bacteremia. CONCLUSIONS: 1) Pyelonephritis in pregnant women is associated with an increased plasma concentration of C5a, but not C3a and C4a; and 2) an excess of C5a can predispose pregnant women to develop ARDS and multi-organ failure in pyelonephritis. This finding may have clinical implications since blocking C5a improves ARDS in experimental sepsis.

Acute Disease↗

PubMed2005

Anaphylatoxins in preterm and term labor.

OBJECTIVE: The complement system plays a central role in the first line of defense against invading pathogens, and its activation involves the release of potent pro-inflammatory mediators such as anaphylatoxins C3a, C4a and C5a. The aim of this study was to determine whether differences existed in maternal plasma anaphylatoxin concentrations between patients with term and preterm parturition. STUDY DESIGN: A cross-sectional study was designed to determine the plasma anaphylatoxin concentrations in 296 pregnant women in the following groups: 1) normal pregnancy between 20-36 6/7 weeks (n=64); 2) term not in labor (n=70); 3) term in labor (n=60); and 4) preterm labor with intact membranes (n=102). Women with preterm labor were classified into: a) term delivery (n=24); b) preterm delivery without intra-amniotic infection (IAI) (n=62); and c) preterm delivery with IAI (n=16). Concentrations of C3a, C4a and C5a were determined by ELISAs. Statistical analysis was conducted with non-parametric methods. RESULTS: 1) The median plasma C5a concentration was lower in women at term in labor than in those not in labor (P<0.001). In contrast, there were no differences in plasma C3a and C4a concentrations between the two groups (P>0.05). 2) Among patients with preterm labor, those with IAI had a higher median plasma C5a concentration than those without IAI and those who delivered at term (post-hoc tests P<0.001 and P=0.01, respectively). When comparing the preterm labor subgroups with normal pregnancy, only women with preterm delivery and IAI had a median plasma C5a concentration higher than that of normal pregnant women (Kruskal-Wallis P<0.001, post hoc test P<0.001). There was no difference in the plasma C4a concentration among patients with preterm labor. The median plasma C3a concentration in patients with preterm labor with IAI was higher than in those without IAI (Kruskal-Wallis P=0.01, and post-hoc test P=0.005). There was no difference in the plasma C3a concentrations between women with preterm labor who delivered at term and those with preterm delivery, with or without IAI. In addition, no differences were observed in the median plasma C3a concentration between women with normal pregnancy and those in each of the preterm labor subgroups. CONCLUSIONS: The maternal plasma concentration of anaphylatoxin C5a is increased in women with preterm labor and IAI, but not in spontaneous labor at term.

Adolescent↗

PubMed2005

Unexplained intrauterine fetal death is accompanied by activation of complement.

OBJECTIVE: Activation of the complement system has recently been implicated in the mechanisms of fetal loss in the antiphospholipid syndrome. It is, however, possible that complement activation is also involved in other causes of fetal death in the second and third trimesters of pregnancy. We therefore conducted a study to determine whether fetal death is associated with changes in the maternal plasma concentrations of complement split products or anaphylatoxins (C3a, C4a and C5a). STUDY DESIGN: A cross-sectional study was designed to include normal pregnant women (n=60) and patients with fetal death (n=60). Patients with fetal death were classified according to the cause of fetal demise into: a) unexplained (n=44); b) associated with preeclampsia (n=8); and c) associated with chromosomal abnormalities or major congenital fetal anomalies (n=8). The plasma concentrations of C3a, C4a and C5a were measured using sensitive and specific ELISAs. Non-parametric statistics were used for analysis. A P value of <0.05 was considered significant. RESULTS: 1) The median plasma concentration of C5a was higher in patients with fetal death than in normal pregnant women [median 16 ng/mL (range 4.5-402.5) vs. median 11.6 ng/mL (range 1.2-87.1), respectively; P<0.001]; 2) patients with an unexplained fetal death and those associated with preeclampsia had a higher median plasma C5a concentration than normal pregnant women (P=0.002 and P<0.001, respectively); 3) no differences were observed in the maternal plasma concentrations of C3a and C4a among the study groups. CONCLUSIONS: Unexplained fetal death is associated with evidence of complement activation.

Adolescent↗