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Biomedical subjects

Roberto Romero

Publications and source records attributed to Roberto Romero.

At least 127 records · Page 7Linked to original sources
PubMed2003

Micronutrients and intrauterine infection, preterm birth and the fetal inflammatory response syndrome.

Prematurity is the leading cause of perinatal morbidity and mortality worldwide. Intrauterine infection has emerged as a major cause of premature labor and delivery. It has been estimated that 25% of all preterm deliveries occur to mothers who have microbial invasion of the amniotic cavity, although these infections are mostly subclinical in nature. This article describes the pathways leading to intrauterine infection, microbiology, frequency and clinical consequences of infection. The pathophysiology of the fetal inflammatory response syndrome is reviewed, as is its relationship to long-term handicap, such as cerebral palsy and bronchopulmonary dysplasia. A possible role for two micronutrients, vitamins C and E, in the prevention of the preterm prelabor rupture of membranes and the consequences of fetal inflammation is considered. Research needs are listed.

Female↗
PubMed2003

Macrophage inhibitory cytokine 1 in fetal membranes and amniotic fluid from pregnancies with and without preterm labour and premature rupture of membranes.

The placenta and fetal membranes are the site of expression of macrophage inhibitory cytokine (MIC-1), a member of the transforming growth factor (TGF)-beta superfamily. We hypothesized that MIC-1 may act as an immune regulator in pregnancy complications associated with intrauterine inflammation. Decidual cells, chorionic trophoblasts and amnion epithelial cells were identified by immunohistochemistry as the predominant MIC-1-containing cell type in term membranes. Amnion and choriodecidual explants all produced MIC-1 in culture, the latter having the greatest production rate (206 +/- 74.5 pg/mg tissue/24 h, n=6; mean +/- SEM). Production was not responsive to stimulation by pro-inflammatory cytokines. MIC-1 was detectable in 217 transabdominal amniotic fluid (AF) samples taken from 15 to 41 weeks gestation, concentrations ranging from 0.9-51.1 ng/ml. AF MIC-1 concentrations in pregnancies with premature rupture of membranes (PROM) or preterm labour, either with or without microbial invasion of the amniotic cavity, were not significantly different from those delivered at term either with or without labour. Treatment with MIC-1 (0.25-25 ng/ml) did not alter production of interleukin-6 or -8 by amnion or choriodecidual cells in vitro. We conclude that AF MIC-1 is derived from the fetal membranes and decidua, but that MIC-1 is unlikely to be involved in the pathophysiology of preterm birth or PROM.

Amniotic Fluid↗
PubMed2003

Matrix metalloproteinase 3 in parturition, premature rupture of the membranes, and microbial invasion of the amniotic cavity.

OBJECTIVE: Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that are expressed in many inflammatory conditions and contribute to connective tissue breakdown. Stromelysin 1 [matrix metalloproteinase 3 (MMP-3)], a novel member of this family, is produced in the context of infection and is able to activate the latent forms of other MMPs. The purpose of this study was to determine if parturition (either term or preterm), premature rupture of the membranes (PROM), and microbial invasion of the amniotic cavity are associated with changes in amniotic fluid concentrations of MMP-3. STUDY DESIGN: A cross-sectional study was conducted, which included women who underwent transabdominal amniocentesis (n = 365) in the following categories: (1) mid-trimester with a subsequent normal pregnancy outcome (n = 84) and a subsequent fetal loss (n = 10); (2) preterm labor with intact membranes without microbial invasion of the amniotic cavity who delivered at term (n = 36), or prematurely (n = 50), and preterm labor with microbial invasion of the amniotic cavity (n = 25); (3) preterm PROM with (n = 25) and without (n = 26) microbial invasion of the amniotic cavity; (4) term with intact membranes in the absence of microbial invasion of the amniotic cavity, in labor (n = 52) and not in labor (n = 31); and (5) term with PROM in the absence of microbial invasion of the amniotic cavity and not in labor (n = 26). MMP-3 concentrations in amniotic fluid were measured by a sensitive and specific immunoassay that was validated for amniotic fluid. MMP-3 concentrations were normalized using logarithmic transformation for statistical analysis. Parametric statistics were used and a p value < 0.05 was considered statistically significant. RESULTS: (1) MMP-3 was detected in 99.5% (363/365) of amniotic fluid samples, and its concentration did not change with advancing gestational age. (2) Spontaneous parturition at term and preterm was associated with a significant increase in amniotic fluid MMP-3 concentrations (p = 0.04 and p = 0.002, respectively). (3) Spontaneous rupture of membranes in term and preterm gestations was not associated with significant changes in amniotic fluid MMP-3 concentrations. (4) Intra-amniotic infection was associated with a significant increase in amniotic fluid MMP-3 concentrations in both women with preterm labor and intact membranes (p = 0.03), and women with preterm PROM (p = 0.02). (5) Subsequent fetal loss after genetic amniocentesis was not associated with significant changes in mid-trimester concentrations of amniotic fluid MMP-3. CONCLUSIONS: (1) MMP-3 is a physiologic constituent of amniotic fluid. (2) MMP-3 may play a role in the mechanisms of human parturition and in the regulation of the host response to intrauterine infection.

Amnion↗
PubMed2003

Biovar diversity of Ureaplasma urealyticum in amniotic fluid: distribution, intrauterine inflammatory response and pregnancy outcomes.

OBJECTIVE: The objective of this study was to determine the distribution of two biovars of Ureaplasma urealyticum (parvo and T960) in human amniotic fluid and to examine whether the magnitude of the intrauterine inflammatory response and pregnancy outcomes are different between patients with microbial invasion of the amniotic cavity with "parvo biovar" and those with "T960 biovar". STUDY DESIGN: This cohort included 77 preterm singleton pregnancies (gestational age < 37 weeks) in whom U. urealyticum was detected from amniotic fluid using the polymerase chain reaction (PCR). Amniotic fluid was obtained by transabdominal amniocentesis. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as mycoplasmas. U. urealyticum was biotyped by PCR methods. Amniotic fluid inflammatory response was determined by amniotic fluid white blood cell count and interleukin-6 concentration. RESULTS: 1) The "parvo biovar" was detected in 82% (63/77) and "T960 biovar" was in 18% (14/77) of cases; 2) U. urealyticum was isolated by conventional culture method from amniotic fluid in 56% (35/63) of cases with positive for "parvo biovar" and in 50% (7/14) of cases with positive for "T960 biovar"; 3) There were no significant differences in the median gestational age at amniocentesis, gestational age at delivery, birth weight, amniotic fluid white blood cell count, amniotic fluid interleukin-6 concentration and the rates of clinical chorioamnionitis, histologic chorioamnionitis, funisitis and neonatal morbidity between patients in the two biovar groups. CONCLUSIONS: 1) The "parvo biovar" is more frequently isolated from amniotic fluid of preterm gestations than the "T960 biovar"; 2) Biovar diversity of U. urealyticum in amniotic fluid was not associated with different pregnancy outcome and magnitude of the intraamniotic inflammatory response.

Amniocentesis↗
PubMed2003

Nasal bone evaluation in fetuses with Down syndrome during the second and third trimesters of pregnancy.

OBJECTIVE: This study examined the use of three-dimensional ultrasonography for evaluating the fetal nasal bone, as a sonographic marker of Down syndrome, during the second and early third trimesters of pregnancy. METHODS: Forty fetuses, including 20 with trisomy 21, were scanned once by three-dimensional ultrasonography. A midline sagittal view of the facial profile was used to analyze the volume data. Independent examiners reviewed blinded and randomly allocated volume data sets for the nasal bone. Interobserver reliability was evaluated for the sonographic presence or absence of the nasal bone. Logistic regression determined the contribution of this parameter to the presence of Down syndrome. RESULTS: Both examiners showed substantial agreement in scoring whether the nasal bone was visualized by three-dimensional ultrasonography (P < .001). They identified 40% to 45% of fetuses with abnormalities using the absence of the nasal bone as a sonographic marker. However, a substantial number of fetuses with abnormalities were also found to have a nasal bone present. The nasal bone was visualized in 80% to 90% of fetuses without abnormalities. CONCLUSIONS: Three-dimensional ultrasonography can be used to evaluate the fetal nasal bone with substantial interobserver agreement during the second and early third trimesters of pregnancy. A nonvisualized nasal bone identified 40% to 45% of fetuses with Down syndrome in this study.

Down Syndrome↗
PubMed2003

Three-dimensional power Doppler ultrasonography during pregnancy.

OBJECTIVES: To present the appearance of fetal and placental vascular anatomic structures by three-dimensional power Doppler ultrasonography. METHODS: Three-dimensional multiplanar imaging, surface rendering, and volume rendering were combined with power Doppler ultrasonography to show the methods, imaging artifacts, and diagnostic potential of this technology during pregnancy. RESULTS: Fetuses with normal and abnormal vascular anatomic structures were evaluated by three-dimensional power Doppler ultrasonography. The combination of several imaging modalities (e.g., three-dimensional multiplanar imaging, surface rendering, and volume rendering) with power Doppler ultrasonography is shown. CONCLUSIONS: Three-dimensional power Doppler ultrasonography is an important adjunctive method that can be used to characterize normal vascular development and circulatory anomalies of the fetus.

Female↗
PubMed2003

Genetic sonography: an option for women of advanced maternal age with negative triple-marker maternal serum screening results.

OBJECTIVE: To determine whether offering genetic sonography to patients 35 years of age and older with negative maternal serum triple-marker screening results will result in an increase in the detection rate of trisomy 21. METHODS: The detection rate of trisomy 21 was determined in women 35 years of age and older whose pregnancies were managed according to the following 3 policies: policy I, universal amniocentesis; policy II, maternal serum triple-marker screening followed by amniocentesis only in high-risk women (risk >1:190); and policy III, genetic sonography in women with negative maternal serum screening results (policy II). Policy III included the offering of genetic amniocentesis to patients with abnormal genetic sonographic findings. The rate of acceptance of genetic amniocentesis was modeled, as was the sensitivity (50%-90%) and false-positive rate (5%-25%) of genetic sonography. RESULTS: The number of fetuses expected to have trisomy 21 was 784. For patients evaluated under policy II, 86.3% of fetuses with trisomy 21 were detected. On the basis of the detection rate for trisomy 21 of policy II, the addition of fetuses with trisomy 21 identified under policy III was significantly (P < .01) increased (93.2% to 98.6%) for genetic sonographic sensitivities ranging between 50% and 90%. CONCLUSIONS: A policy of offering genetic sonography followed by amniocentesis to patients 35 years of age and older who originally had triple-marker maternal serum screening findings that were negative for the diagnosis of trisomy 21 results in a higher overall detection rate of trisomy 21.

Adult↗
PubMed2002

Pre-eclampsia and expression of heparin-binding EGF-like growth factor.

BACKGROUND: Pre-eclampsia is a disorder of pregnancy associated with poor extravillous cytotrophoblast invasion and above-normal rates of apoptosis in the trophoblast. Heparin-binding epidermal-growth-factor-like growth factor (HB-EGF) has strong cytoprotective activity and is an important signalling protein that regulates trophoblast invasion during early placentation. We aimed to establish whether HB-EGF expression is altered in placentae of pre-eclamptic women. METHODS: We assessed the expression of HB-EGF mRNA and protein by in-situ hybridisation and immunohistochemical techniques, respectively, in archived placental tissues from pregnancies terminated at around 20 weeks of gestation, and from women delivering between weeks 19 and 35 of gestation with preterm labour, small for gestational age infants, or pre-eclampsia. FINDINGS: HB-EGF mRNA and protein were expressed in villous and extravillous cytotrophoblast cells up to week 35 of gestation in placentae from women who delivered preterm. Similar levels of HB-EGF protein were found in the placentae of women who were not in labour. HB-EGF expression was reduced about five-fold (p=0.0001) in pre-eclamptic pregnancies. Fetal growth retardation, which has been linked with shallow trophoblast invasion and moderate apoptosis, was associated with placentae expressing intermediate levels of HB-EGF. INTERPRETATION: In pre-eclampsia, deficient HB-EGF signalling during placental development could impair trophoblast survival, differentiation, and invasion, leading to poor placental perfusion and hypertension.

Adult↗
PubMed2002

Characterization of selected Spanish table wine samples according to their biogenic amine content from liquid chromatographic determination.

Pattern recognition techniques, such as principal component analysis, cluster analysis, and linear discriminant analysis, have been applied to samples of red, white, and rosé wines to determine whether some biogenic amines could be considered as chemical descriptors. Eight amines (tryptamine, phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine) were determined by RP-HPLC, after derivatization with dabsyl chloride. However, only putrescine, cadaverine, histamine, tyramine, spermidine, and spermine were found in the wines analyzed. From the association between variables obtained by principal component analysis and clustering and from the relationship found by linear discriminant analysis, it can be deduced that the amines generated during malolactic fermentation (putrescine, histamine, and tyramine) could be used as chemical descriptors to characterize table wine samples.

Analysis of Variance↗
PubMed2002

Intrauterine infection and prematurity.

Intrauterine infection is a major cause of premature labor with and without intact membranes. Intrauterine infection is present in approximately 25% of all preterm births and the earlier the gestational age at delivery, the higher the frequency of intra-amniotic infection. Microorganisms may also gain access to the fetus before delivery. A fetal inflammatory response syndrome elicited in response to microbial products is associated with the impending onset of preterm labor and also with multi-systemic organ involvement in the human fetus and a higher rate of perinatal morbidity. The most common microorganisms involved in intrauterine infections are Ureaplasma urealyticum, Fusobacterium species and Mycoplasma hominis. The role of Chlamydia trachomatis and viruses in preterm labor remain to be determined. Use of molecular microbiology techniques to diagnose intrauterine infection may uncover the role of fastidious microorganisms that have not yet been discovered. Antibiotic administration to patients with asymptomatic bacteriuria is associated with a significant reduction in the rate of preterm birth. However, such benefit has not been demonstrated for patients with bacterial vaginosis, or women who carry Streptococcus agalactia, Ureaplasma urealyticum or Trichomonas vaginalis. Antibiotic administration to patients with preterm premature rupture of membranes is associated with prolongation of pregnancy and a reduction in the rate of clinical chorioamnionitis and neonatal sepsis. The benefit has not been demonstrated in patients with preterm labor and intact membranes. Major efforts are required to determine why some women develop an ascending intrauterine infection and others do not and also what interventions may reduce the deleterious effect of systemic fetal inflammation.

Amniotic Fluid↗
PubMed2002

Infection and prematurity and the role of preventive strategies.

This article reviews the role of infection in spontaneous premature parturition, the pathways of ascending intrauterine infection, microbiology, and the frequency of intra-amniotic infection in obstetrical complications leading to premature delivery. The evidence that infection is causally linked to premature birth is critically examined, as is the relationship between urogenital tract infection/colonization with microorganisms and the risk of preterm birth. The effect of antibiotic administration in perinatal outcome in patients with preterm labor and intact membranes, preterm premature rupture of membranes, asymptomatic bacteriuria, Group B streptococcus and genital mycoplasmas of the lower genital tract, and bacterial vaginosis are critically examined.

Amniotic Fluid↗
PubMed2002

Endogenous mast cell degranulation modulates cervical contractility in the guinea pig.

OBJECTIVE: The purpose of this study was to investigate the effect of endogenous mast cell degranulation on the contractility of isolated cervical strips from nonpregnant and pregnant guinea pigs. STUDY DESIGN: Longitudinal cervical strips from nonpregnant and pregnant (mid and term) guinea pigs were used for isometric tension recording. Responses to the mast cell degranulating agent, compound 48/80, were compared in the absence or presence of different inhibitors and receptor antagonists. Concentration-response curves were obtained to histamine and 5-hydroxytryptamine in strips that were incubated with antagonists or solvent. RESULTS: Compound 48/80 and histamine significantly increased contractility of cervical strips in all 3 groups of animals. The inhibitor of mast cell degranulation significantly reduced responses to compound 48/80 and histamine-1 receptor antagonist reduced responses to histamine in all 3 groups. Histamine-1 receptor antagonist significantly inhibited responses to compound 48/80 in nonpregnant and mid pregnant guinea pigs. Histamine-2 receptor antagonist did not alter responses to compound 48/80 nor to histamine. The receptor antagonist 5-hydroxytryptamine-2 significantly inhibited cervical contractility that was induced by compound 48/80 in tissues from mid pregnant and term pregnant guinea pigs. Lipoxygenase inhibitor was effective in mid pregnant guinea pigs. Cyclooxygenase inhibitor, 5-hydroxytryptamine, and a combination of lipoxygenase and cyclooxygenase inhibitors had no effect on cervical contractility. CONCLUSION: The degranulation of mast cells releases histamine and other mediators that stimulate cervical contractility through histamine-1 receptors. Cervical infiltration and modulation of contractility by mast cells may play an important physiologic and/or pathologic role in the control of cervical function during pregnancy.

Animals↗
PubMed2002

Evidence for fetal involvement in the pathologic process of clinical chorioamnionitis.

OBJECTIVE: Clinical and histologic chorioamnionitis have recently been identified as risk factors for cerebral palsy. Proinflammatory cytokines have been implicated in the mechanisms that are responsible for brain injury in cases of intrauterine infection. The purpose of this study was to determine whether clinical chorioamnionitis, which is a maternal syndrome, is associated with an elevation in the fetal plasma interleukin-6 (IL-6) that is indicative of fetal inflammation. STUDY DESIGN: A cross-sectional study was designed to determine plasma concentrations of IL-6 in umbilical venous blood from patients with clinical chorioamnionitis (n = 26) and a control group (n = 111). Umbilical cord blood was obtained at the time of delivery. Plasma concentrations of IL-6 were measured with a sensitive and specific immunoassay. Nonparametric statistics were used for analysis. RESULTS: Plasma concentrations of IL-6 were detectable in all samples of umbilical venous plasma. The median concentration of plasma IL-6 was higher in neonates born to mothers with clinical chorioamnionitis than in neonates born to mothers in the control group (clinical chorioamnionitis: median, 27.46 pg/mL; range, 1.3-5550.0 pg/mL; vs control: median, 2.13 pg/mL; range, 0.6-812.3 pg/mL; P <.001). Sixty-two percent of neonates (16/26) who were born to women with clinical chorioamnionitis had fetal plasma concentrations of IL-6 >11 pg/mL and 54% (14/26) had fetal plasma concentrations of IL-6 >18 pg/mL (these cutoff points have been used previously to define the fetal inflammatory response syndrome). CONCLUSION: Umbilical vein plasma concentrations of interleukin-6 are elevated in the neonates who were born to mothers with clinical chorioamnionitis, which suggests that the inflammatory process that is responsible for the maternal syndrome of clinical chorioamnionitis frequently involves the human fetus.

Adolescent↗
PubMed2002

Maternal lymphocyte subpopulations (CD45RA+ and CD45RO+) in preeclampsia.

OBJECTIVE: The maternal syndrome of preeclampsia has been attributed to a systemic intravascular inflammatory response and endothelial cell dysfunction. The stimulus responsible for intravascular inflammation in preeclampsia has not been determined. The expression of CD45 isoforms on the surface of human T cells has been used to classify CD4(+) T lymphocytes into naïve cells (CD45RA+) and memory T cells (CD45RO+). An increased percentage of CD45RO+ cells has been interpreted as consistent with previous exposure to microbial products or other antigens. The purpose of this study was to determine whether preeclampsia is associated with a change in the proportion of CD45RA+ and CD45RO+. STUDY DESIGN: A prospective study was conducted in patients with preeclampsia (n = 24) and normal pregnancy (n = 75). The percentage of CD45RA+ and CD45RO+ on CD4(+) T lymphocytes in peripheral blood was determined using flow cytometry and monoclonal antibodies. Results were reported as a percentage of CD4(+) lymphocytes. Parametric statistics were used for analysis. A probability value of <.05 was considered statistically significant. RESULTS: Patients with preeclampsia had a significantly higher percentage of CD45RO+ than normal pregnant women (P <.01). A significantly lower percentage of CD45RA+ was found in patients with preeclampsia than in normal pregnant women (P <.01). CONCLUSION: Preeclampsia is associated with an increase in the percentage of CD45RO+ and a decrease in the CD45RA+ lymphocyte subpopulation. Therefore, patients with preeclampsia have evidence of previous antigenic exposure, the nature of which remains to be established.

Adult↗
PubMed2002

Fetal plasma MMP-9 concentrations are elevated in preterm premature rupture of the membranes.

OBJECTIVE: The objective of this study was to determine whether the concentrations of matrix metalloproteinase-9 (MMP-9) in the fetal (fetal plasma and amniotic fluid) and maternal compartments (plasma) are different in patients presenting with preterm premature rupture of membranes (PROM) than in those with preterm labor and intact membranes. STUDY DESIGN: Fetal plasma MMP-9, interleukin-1beta (IL-1beta), IL-6, soluble tumor necrosis factor receptors 1 (sTNF-R1) and 2 (sTNF-R2) were measured in fetuses with preterm labor and intact membranes (n = 96) and preterm PROM (n = 43). The concentrations of analytes were determined with sensitive and specific immunoassays. A P value <.05 was considered significant. RESULTS: (1) The median fetal plasma MMP-9 concentration was significantly higher in fetuses with preterm PROM than in those with preterm labor (P =.035). (2) In contrast, fetal plasma IL-1beta, sTNF-R1, and sTNF-R2 were significantly higher in patients with preterm labor than in those with preterm PROM (IL-1beta, P =.01; sTNF-R1, P =.003; and sTNF-R2, P =.02). (3) The median amniotic fluid concentration of MMP-9 was higher in patients with preterm PROM than in those with preterm labor (P <.001). CONCLUSION: Fetuses with preterm PROM have increased concentrations of an enzyme (MMP-9) implicated in the mechanism of membrane rupture but lower concentrations of IL-1beta, sTNF-R1, and sTNF-R2 than fetuses with preterm labor and intact membranes. A role for the fetus in the genesis of preterm PROM deserves consideration.

Adolescent↗
PubMed2002

Failure of physiologic transformation of the spiral arteries in the placental bed in preterm premature rupture of membranes.

OBJECTIVE: The purpose of this study was to determine whether failure of physiologic transformation of the spiral arteries occurs in patients with preterm premature rupture of membranes (PROM). STUDY DESIGN: A cross-sectional study was designed to examine the histopathologic findings in the placental bed and placenta of patients with preterm PROM, preeclampsia, and normal women at term. Immunohistochemistry with cytokeratin 7 and periodic acid-Schiff (PAS) were used to detect trophoblast and fibrinoid and to diagnose failure of physiologic transformation of the spiral arteries. RESULTS: One hundred thirteen cases met the inclusion criteria, 59 from patients with normal pregnancies, 31 with preterm PROM, and 23 with preeclampsia. The mean number of the spiral arteries with failure of physiologic transformation of the myometrial segment was significantly higher in patients with preterm PROM and preeclampsia than in normal pregnant women at term (P =.006 and P <.0001, respectively). In contrast, the mean number of the spiral arteries with failure of physiologic transformation of the decidual segment of the spiral arteries in the basal plate of the placenta was not significantly different in patients with preterm PROM from that in normal pregnant women (P >.05). Placentas from patients with preterm PROM had a higher frequency of vascular lesions than those from normal pregnant women (P =.02). CONCLUSION: Defective placentation, defined as failure of physiologic transformation of the myometrial segment of the spiral artery, is frequently present in preterm PROM.

Adult↗
PubMed2002

The design, execution, and interpretation of genetic association studies to decipher complex diseases.

Genetic association studies are becoming increasingly frequent in the obstetric and gynecologic literature and they are considered central to the deciphering of the genetic basis of complex disease. The purpose, design, execution, analysis, and interpretation of genetic association studies in reproduction are discussed. Frequently used terms are defined (eg, genotype, haplotype, polymorphism, single nucleotide polymorphism, linkage disequilibrium). Guidelines are proposed for the evaluation of reports of genetic association studies (including selection of polymorphisms for study, study design, assay characteristics, sample size, multiple testing, and multivariable analysis). The potential value of this type of investigation in elucidating the mechanisms of disease in reproduction is illustrated.

Genetic Diseases, Inborn↗