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Biomedical subjects

Roberto Romero

Publications and source records attributed to Roberto Romero.

At least 109 records · Page 6Linked to original sources
PubMed2004

Induction of premature labor and delivery by allergic reaction and prevention by histamine H1 receptor antagonist.

OBJECTIVE: The purpose of this study was to determine whether type I hypersensitivity can induce preterm labor and delivery that may be prevented by the administration of an H 1 receptor antagonist or a mast-cell stabilizer. STUDY DESIGN: At days 40 through 50 of gestation, ovalbumin-sensitized guinea pigs that had not been treated or had been pretreated with an H 1 receptor antagonist (ketotifen) or a mast-cell stabilizer (cromolyn sodium) were challenged with either ovalbumin or saline solution. Nonsensitized guinea pigs were challenged with ovalbumin. RESULTS: The duration of gestation was significantly shorter in sensitized animals that were challenged with ovalbumin than in the other groups. Pretreatment with ketotifen significantly increased the duration of pregnancy in sensitized animals, compared with untreated animals. Cromolyn sodium had no effect. CONCLUSION: An allergic reaction can induce premature labor/delivery, and pretreatment with histamine H 1 receptor antagonist can prevent it. These observations provide evidence of a novel mechanism of disease for premature labor and delivery.

Allergens↗
PubMed2004

Toll-like receptor-2 and -4 in the chorioamniotic membranes in spontaneous labor at term and in preterm parturition that are associated with chorioamnionitis.

OBJECTIVE: The Toll-like receptor-2 and -4 recognize microbial products that are associated with gram-positive and gram-negative bacteria, respectively. This study examined Toll-like receptor-2 and -4 expression in fetal membranes in response to labor at term and histologic chorioamnionitis. STUDY DESIGN: Immunohistochemistry and real-time quantitative reverse transcriptase-polymerase chain reaction were used to examine the chorioamnion from patients with (1) preterm labor and intact membranes, (2) preterm premature rupture of membranes who were delivered < or =34 weeks of gestation, and (3) women at term with or without labor. All groups were stratified on the basis of the presence of histologic chorioamnionitis. RESULTS: Toll-like receptor-2 expression was significantly higher in patients with chorioamnionitis than in patients without this condition (all P < .05). The Toll-like receptor-2 and -4 messenger RNA amounts were significantly higher in membranes from women at term with spontaneous labor than women who were not in labor ( P = .001 and .002, respectively). Toll-like receptor-2 expression was polarized to the basal surface of amniotic epithelial cells in patients without chorioamnionitis, but this distribution was lost in the presence of inflammation. CONCLUSION: Spontaneous labor at term and preterm delivery with histologic chorioamnionitis, regardless of the membrane status (intact or ruptured), are associated with an increased expression of Toll-like receptor-2 and -4 in the chorioamniotic membranes. These observations have implications for understanding the biologic nature of innate immunity.

Amnion↗
PubMed2004

Genome-wide expression profiling of fetal membranes reveals a deficient expression of proteinase inhibitor 3 in premature rupture of membranes.

OBJECTIVE: We used a genome-wide approach to identify differentially expressed genes in patients with preterm premature rupture of membranes to improve the understanding of underlying molecular mechanisms. STUDY DESIGN: RNA was isolated from the fetal membranes of patients with preterm labor with intact membranes and preterm premature rupture of membranes and was stratified according to the presence or absence of histologic chorioamnionitis. Microarray experiments were used to identify differentially expressed genes, and real-time quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry were used in follow-up experiments. RESULTS: Microarray experiments identified decreased expression of proteinase inhibitor 3 in the preterm premature rupture of membranes cases. Quantitative reverse transcriptase-polymerase chain reaction confirmed these results. Immunohistochemistry demonstrated decreased proteinase inhibitor 3 protein expression in preterm premature rupture of membranes. CONCLUSION: A genome-wide approach identified deficient expression of proteinase inhibitor 3 in preterm premature rupture of membranes, which demonstrated the usefulness of functional genomics for the dissection of mechanisms of disease and identification of differentially regulated genes that were not suspected previously to play a role in parturition.

Acute Disease↗
PubMed2004

Can endometrial infection/inflammation explain implantation failure, spontaneous abortion, and preterm birth after in vitro fertilization?

The endometrial cavity is frequently invaded by microorganisms, and subclinical endometrial infection or inflammation may play a role in implantation failure after IVF, spontaneous abortion, and preterm birth. Microbial products and host-inflammatory mediators such as cytokines and chemokines can cause trophoblast apoptosis and the cascade of events leading to expulsion of the embryo or fetus.

Abortion, Spontaneous↗
PubMed2004

Macrophages and apoptotic cell clearance during pregnancy.

BACKGROUND: During implantation, apoptosis is critical for the appropriate tissue remodeling of the maternal decidua and invasion of the developing embryo, yet the regulation of apoptosis is also imperative for a successful pregnancy. The quick and effective removal of apoptotic cells by tissue macrophages represents an essential process, which prevents the release of self-antigens, and in the case of pregnancy, paternal alloantigens. METHODS OF STUDY: Recent studies have shown that the process of apoptotic cell clearance is not a neutral event, but rather an active one that induces macrophage production of anti-inflammatory cytokines and survival factors. Apoptotic cell clearance is, therefore, necessary for the resolution of inflammatory conditions, which during pregnancy could have lethal consequences. CONCLUSIONS: The function of the maternal immune system during implantation and throughout pregnancy is, therefore, an important area of investigation. This review will discuss the role of decidual macrophages in apoptotic cell clearance during pregnancy.

Apoptosis↗
PubMed2004

The use of the minimum projection mode in 4-dimensional examination of the fetal heart with spatiotemporal image correlation.

OBJECTIVE: The minimum projection mode (MPM) is a rendering algorithm available in some 3- and 4-dimensional ultrasonography systems that, in 1 image, allows the visualization of vessels and cystic anatomic structures located in different scanning planes. The objective of this study was to compare the information displayed in images obtained with the MPM with their corresponding 2-dimensional ultrasonographic images from fetuses with and without structural heart defects. METHODS: Thirty-two volume data sets acquired with the spatiotemporal image correlation technique from fetuses with (n = 15) and without (n = 17) structural heart defects were analyzed. Rendered images of the upper abdomen, 4-chamber view, and 3-vessel view were compared with the corresponding 2-dimensional images. Two independent observers with experience in fetal echocardiography reviewed these volume data sets using the MPM. The visualization rate of specific anatomic structures seen from a transverse sweep of the heart was recorded for each observer, and the interobserver agreement was assessed by statistical indices of agreement (kappa statistic). RESULTS: Images obtained by the MPM displayed more vascular structures than those of corresponding 2-dimensional images at the level of the 3-vessel view. For conotruncal anomalies, the minimum mode projected the aorta and pulmonary arteries in 1 single plane, facilitating the understanding of their spatial relationships. The interobserver agreement score was moderate to "almost perfect" for assessment of most anatomic structures in the upper abdomen, 4-chamber view, and 3-vessel view sections. However, interobserver agreement ranged from fair to poor for visualization of the left outflow tract, atrial septum, and flap of the foramen ovale. CONCLUSIONS: The MPM is an alternative rendering modality that facilitates visualization of normal and abnormal vascular connections to the fetal heart at the level of the 3-vessel view. This technique may be useful in prenatal diagnosis of conotruncal anomalies and in assessment of the spatial relationships of abnormal vascular connections in the upper mediastinum.

Algorithms↗
PubMed2004

Phenotypic characteristics of absent and hypoplastic nasal bones in fetuses with Down syndrome: description by 3-dimensional ultrasonography and clinical significance.

OBJECTIVE: To determine the frequency and clinical significance of bilateral and unilateral hypoplastic nasal bones for the detection of Down syndrome by 3-dimensional ultrasonography. METHODS: Thirty-seven volumes of the fetal skull from fetuses with Down syndrome and 37 from fetuses without abnormalities were analyzed by 1 investigator blinded to fetal karyotype. The maximum intensity projection algorithm was used to reconstruct nasal bones. Ossification patterns were identified in anteroposterior and profile views. Sensitivity, false-positive rates (FPRs), and likelihood ratios (LRs) for detection of Down syndrome were calculated. RESULTS: After exclusions (coronal acquisition [n = 11], hand in front of the face [n = 4], poor imaging [n = 2], incomplete follow-up [n = 2], and anomalies detected after delivery [n = 2]), 53 volumes were analyzed (26 fetuses with Down syndrome and 27 without abnormalities; median gestational age, 21 6/7 weeks [interquartile range, 19 6/7-25 2/7 weeks]). Rendered profile views revealed absent nasal bones in 18.9% (10 of 53) of the fetuses, and, among these, 90% (9 of 10) had Down syndrome (sensitivity, 34.6% [9 of 26]; FPR, 3.7% [1 of 27]; LR, 9.3 [95% confidence interval (CI), 1.3-68.7]). Three ossification patterns were identified in anteroposterior views: (1) normally developed, (2) delayed ossification, and (3) absent nasal bones. Sensitivity, FPR, and LR of absent nasal bones for detecting Down syndrome were 34.6% (9 of 26), 3.7% (1 of 27), and 9.0 (95% CI, 1.3-68.7), respectively. Sensitivity, FPR, and LR of delayed ossification for detecting Down syndrome were 42.3% (11 of 26), 22% (6 of 27), and 1.83 (95% CI, 0.8-4.4). CONCLUSIONS: Absence of nasal bones is associated with the highest risk of Down syndrome. Delayed ossification is associated with a lower risk of Down syndrome than absent nasal bones. These ossification patterns may be indistinguishable on 2-dimensional ultrasonography.

Down Syndrome↗
PubMed2004

Four-dimensional ultrasonography of the fetal heart using color Doppler spatiotemporal image correlation.

OBJECTIVE: To describe clinical and research applications of 4-dimensional imaging of the fetal heart using color Doppler spatiotemporal image correlation. METHODS: Forty-four volume data sets were acquired by color Doppler spatiotemporal image correlation. Seven subjects were examined: 4 fetuses without abnormalities, 1 fetus with ventriculomegaly and a hypoplastic cerebellum but normal cardiac anatomy, and 2 fetuses with cardiac anomalies detected by fetal echocardiography (1 case of a ventricular septal defect associated with trisomy 21 and 1 case of a double-inlet right ventricle with a 46,XX karyotype). The median gestational age at the time of examination was 21 3/7 weeks (range, 19 5/7-34 0/7 weeks). Volume data sets were reviewed offline by multiplanar display and volume-rendering methods. Representative images and online video clips illustrating the diagnostic potential of this technology are presented. RESULTS: Color Doppler spatiotemporal image correlation allowed multiplanar visualization of ventricular septal defects, multiplanar display and volume rendering of tricuspid regurgitation, volume rendering of the outflow tracts by color and power Doppler ultrasonography (both in a normal case and in a case of a double-inlet right ventricle with a double-outlet right ventricle), and visualization of venous streams at the level of the foramen ovale. CONCLUSIONS: Color Doppler spatiotemporal image correlation has the potential to simplify visualization of the outflow tracts and improve the evaluation of the location and extent of ventricular septal defects. Other applications include 3-dimensional evaluation of regurgitation jets and venous streams at the level of the foramen ovale.

Echocardiography, Four-Dimensional↗
PubMed2003

The influence of the brewing process on the formation of biogenic amines in beers.

Biogenic amines, as dabsyl derivatives, were determined in beer samples, intermediate products, and raw materials (malt and maize) by HPLC. A procedure for the extraction of the amines from malt and maize with diluted hydrochloric acid was optimised by combining a Response Surface Methodology with a Simultaneous Decision Making Approach. The results of the analysis indicate that, in brewing, technology and hygiene are the decisive factors that determine the amine concentrations in the final product.

Beer↗
PubMed2003

Promyelocytic leukaemia (PML) protein expression in human placenta and choriocarcinoma.

Promyelocytic leukaemia (PML) protein, the product of the pml gene, is heterogeneously expressed in various normal and neoplastic tissues, and the fusion of the pml gene with retinoic acid receptor-alpha is believed to be a central mechanism in acute PML tumourigenesis. As PML is important for controlling major cellular processes, such as growth and differentiation, it is believed that it plays an important role during human gestation. The human placenta is a critical organ for the maintenance of gestation, but the expression pattern and functional significance of PML in the placenta have not been documented. The present study has therefore investigated the expression of PML in the human placenta and in choriocarcinoma, and has observed the biological effects following the overexpression of PML in choriocarcinoma cell lines (BeWo and JEG-3). In the human placenta, PML expression was readily found in villous stromal fibroblasts, capillary endothelial cells, Hofbauer cells, and occasionally in amnion cells. Moreover, immunoblotting of placental lysates demonstrated increased PML expression with increasing gestation. Interestingly, PML expression was confined to intermediate trophoblasts and syncytiotrophoblastic giant cells at the placental site (placental site giant cells) in the trophoblastic cell population. Intermediate trophoblasts at non-placental sites, and villous cytotrophoblasts and syncytiotrophoblasts consistently did not express PML. Further screening of PML expression in hydatidiform moles (n = 4) and choriocarcinomas (n = 7) also revealed selective PML expression in intermediate trophoblastic cells and syncytiotrophoblastic cells, but not in the cytotrophoblastic populations, which corresponds well with observations in the placental bed. Adenoviral transduction of PML resulted in a marked reduction in cell growth in both choriocarcinoma cell lines, which was associated with increased apoptosis. The findings of the present study strongly suggest that PML plays an important role in human placental development and growth, and in the pathobiology of trophoblasts and trophoblastic neoplasia.

Choriocarcinoma↗
PubMed2003

Four-dimensional ultrasonography of the fetal heart with spatiotemporal image correlation.

OBJECTIVE: This study was undertaken to describe a new technique for the examination of the fetal heart using four-dimensional ultrasonography with spatiotemporal image correlation (STIC). STUDY DESIGN: Volume data sets of the fetal heart were acquired with a new cardiac gating technique (STIC), which uses automated transverse and longitudinal sweeps of the anterior chest wall. These volumes were obtained from 69 fetuses: 35 normal, 16 with congenital anomalies not affecting the cardiovascular system, and 18 with cardiac abnormalities. Dynamic multiplanar slicing and surface rendering of cardiac structures were performed. To illustrate the STIC technique, two representative volumes from a normal fetus were compared with volumes obtained from fetuses with the following congenital heart anomalies: atrioventricular septal defect, tricuspid stenosis, tricuspid atresia, and interrupted inferior vena cava with abnormal venous drainage. RESULTS: Volume datasets obtained with a transverse sweep were utilized to demonstrate the cardiac chambers, moderator band, interatrial and interventricular septae, atrioventricular valves, pulmonary veins, and outflow tracts. With the use of a reference dot to navigate the four-chamber view, intracardiac structures could be simultaneously studied in three orthogonal planes. The same volume dataset was used for surface rendering of the atrioventricular valves. The aortic and ductal arches were best visualized when the original plane of acquisition was sagittal. Volumes could be interactively manipulated to simultaneously visualize both outflow tracts, in addition to the aortic and ductal arches. Novel views of specific structures were generated. For example, the location and extent of a ventricular septal defect was imaged in a sagittal view of the interventricular septum. Furthermore, surface-rendered images of the atrioventricular valves were employed to distinguish between normal and pathologic conditions. Representative video clips were posted on the Journal's Web site to demonstrate the diagnostic capabilities of this new technique. CONCLUSION: Dynamic multiplanar slicing and surface rendering of the fetal heart are feasible with STIC technology. One good quality volume dataset, obtained from a transverse sweep, can be used to examine the four-chamber view and the outflow tracts. This novel method may assist in the evaluation of fetal cardiac anatomy.

Cohort Studies↗
PubMed2003

Effect of histamine on phasic and tonic contractions of isolated uterine tissue from pregnant women.

OBJECTIVE: To enhance our understanding of the uterotonic effect of histamine, we compared the effects of histamine on spontaneous phasic and tonic contractile activity of uterine strips from term pregnant nonlaboring women. STUDY DESIGN: Longitudinal uterine strips were used from the lower uterine segment of term pregnant nonlaboring women undergoing elective cesarean section. The concentration-response relationship to histamine (10(-8) to 10(-4) mol/L) was determined in spontaneously contracting strips or in strips contracted tonically with a protein kinase C activator (-)-indolactam V in the presence of H(1) receptor antagonist (S[+]-chlorpheniramine maleate), H(2) receptor antagonist (cimetidine), or solvent. RESULTS: Histamine increased spontaneous phasic myometrial contractions in a concentration-dependent manner. H(1), but not H(2), receptor antagonist significantly attenuated the response to histamine. Histamine significantly reduced tonic contractions of uterine strips induced by indolactam V. H(1) histamine receptor antagonist abolished relaxation, whereas H(2) histamine receptor antagonist had no effect. CONCLUSION: Histamine increases spontaneous, but inhibits tonic, contractions of uterine strips from term pregnant nonlaboring women. Both effects are mediated through activation of H(1) receptors.

Chlorpheniramine↗
PubMed2003

Three-dimensional color power imaging of the fetal hepatic circulation.

OBJECTIVE: The purpose of this study was to describe the use of three-dimensional power Doppler ultrasonography to identify vascular congenital anomalies of fetal portosystemic and umbilical venous systems. STUDY DESIGN: In a prospective study, the hepatic and umbilical venous systems were examined in 390 fetuses with two-dimensional ultrasonography, color, and spectral Doppler imaging. Fetuses suspected to have anomalies of the portal system and ductus venosus were additionally examined with three-dimensional power Doppler ultrasonography. RESULTS: Vascular anomalies were identified in 8 fetuses (absent ductus venosus, n=4; direct connection between the umbilical vein and the right atrium, n=2; and direct connection between the umbilical vein and the inferior vena cava, n=2) out of the 310 in which the venous system could be adequately imaged (prevalence=2.6%). Three-dimensional power Doppler imaging showed the course of the umbilical vein, its relationship to the portosystemic circulation, and whether a ductus venosus was present. CONCLUSION: Three-dimensional power Doppler ultrasonography can be used to image normal fetal hepatic and portal circulation, as well as identify anomalies of the fetal portosystemic and umbilical venous systems.

Female↗
PubMed2003

Failure of physiologic transformation of the spiral arteries in patients with preterm labor and intact membranes.

OBJECTIVE: The purpose of this study was to determine whether abnormal placentation (defined as the failure of physiologic transformation of spiral arteries) is present in patients with preterm labor and intact membranes who delivered a preterm neonate. STUDY DESIGN: A cross-sectional study was conducted to examine the histopathologic findings in the placental bed and placenta of patients with preterm labor and intact membranes (n=27), preeclampsia (n=43), and healthy pregnant women at term (n=103). Immunohistochemistry studies with cytokeratin 7 and periodic acid-Schiff were used to detect trophoblast and fibrinoid, respectively, and diagnose the failure of physiologic transformation of the spiral arteries. RESULTS: The mean percentage of spiral arteries with failure of physiologic transformation in the myometrium was significantly higher in patients with preterm labor and preeclampsia than in normal pregnant women at term (P=.0004 and P<.0001, respectively). Similar findings were observed in the decidual segment of spiral arteries within the placental bed (P=.001 and P<.0001). In contrast, the mean percentage of the spiral arteries with failure of physiologic transformation in the decidua of the basal plate was not significantly different between patients with preterm labor and normal pregnant women (P=.17). CONCLUSION: Failure of physiologic transformation of the spiral arteries in the myometrial and decidual segments of the placental bed is frequent in patients with preterm labor and intact membranes.

Adult↗
PubMed2003

The clinical significance of detecting Ureaplasma urealyticum by the polymerase chain reaction in the amniotic fluid of patients with preterm labor.

OBJECTIVE: This study was undertaken to determine the clinical significance of a detection of Ureaplasma urealyticum by using the polymerase chain reaction (PCR) in the amniotic fluid of patients with preterm labor and intact membranes. STUDY DESIGN: Amniocentesis was performed in 257 patients with preterm labor and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as genital mycoplasmas. U urealyticum was detected by PCR using specific primers. Patients were divided into 3 groups according to the results of amniotic fluid culture and PCR for U urealyticum: those with a negative culture and negative PCR (n=228), those with a negative culture but positive PCR (n=6), and those with a positive culture regardless of the results of PCR (n=23). RESULTS: The prevalence of positive amniotic fluid culture was 9% (23 of 257). U urealyticum was detected by PCR in 6% (15 of 254) of cases. Of the 15 cases with positive PCR for U urealyticum, amniotic fluid culture was negative in 40% (6 of 15). Patients with a negative culture but positive PCR for U urealyticum had significantly shorter median amniocentesis-to-delivery interval and higher amniotic fluid interleukin-6 and white blood cell count than those with a negative amniotic fluid culture and negative PCR (P<.01 for each). Patients with a positive PCR for U urealyticum but a negative amniotic fluid culture had a higher rate of significant neonatal morbidity than those with a negative culture and negative PCR (P<.05). However, no significant differences in perinatal outcome were observed between patients with a negative culture but positive PCR and those with a positive amniotic fluid culture. CONCLUSION: Patients with preterm labor and a positive PCR for U urealyticum but negative amniotic fluid culture are at risk for impending preterm delivery and adverse perinatal outcome.

Adult↗