Vasco Bairos

Human chorionic gonadotropin in human placentas from normal and preeclamptic pregnancies

Objective. The aim of this study was to examine the distribution of human chorionic gonadotropin (hCG) in the human placenta of normotensive and preeclamptic pregnancies and to determine by computer image analysis, whether differences in hCG immunoreactivity occurred in preeclamptic as apposed to normotensive pregnancies. We discuss how far elevated maternal serum levels of hCG normally observed in preeclamptic patients reflect an increased secretory activity of the syncytiotrophoblast. Methods. We used the immunoperoxidase technique to locate hCG. Quantification of immunostaining intensity was done by computer image analysis. Results. In normotensive placentas from all the gestational ages human chorionic gonadotrophin immunoreactivity was specifically detected in the syncytiotrophoblast. There is an apparent decrease in the intensity of the hCG immunostaining in the syncytiotrophoblast from the 29th to 36th week of gestation in normotensive placentas. No hCG immunostaining was observed in the villous or extravillous cytotrophoblast of all placentas. In preeclamptic placentas the expression of hCG was homogeneous with a moderate to intense immunoreactivity in the syncytiotrophoblast. Microdensitometric analysis of the section from normotensive and preeclamptic placentas indicated that there is a statistically significant preeclampsia-induced increase in immunohistochemical reaction intensity for hCG (p < 0.05). Conclusion. This study seems to demonstrate that increased production of hCG by preeclamptic placentas is associated with strong hCG immunostaining of the syncytiotrophoblast.

Nanoradioliposomes molecularly modulated to study the lung deep lymphatic drainage

Abstract Lung deep lymphatic drainage (LDLD) plays an important role in the removal of foreign materials from lungs being alveolar macrophages the first line of phagocytic defence with high affinity for pathogenic microorganisms. Bacillus subtilis is a well-known genome- decoded saprophyte of the human respiratory tract used in research and in the biotechnology industry. Lung deep lymphatic chains (LDLC) constitute one of the first sites of lung tumours’ dissemination. In this work we intended to develop and validate a non-invasive method for assessing LDLC by nanoradioliposomes aerosolised modulated on the Bacillus subtilis spore wall. The final goal was to produce a nanoradioliposome formulation that can mimics the dynamics of preferential removal of spores by LDLD and present the ideal properties as a tracer for molecular imaging studies. Seven different liposomal formulations were tested, and the formulation-F demonstrated physicochemical and radiopharmaceutical properties that make it an ideal candidate as an in vivo probe for molecular imaging studies of the LDLC. Nanoradioliposomes of the formulation-F after labelling with 99mTc-HMPAO were administered as aerosols to 20 Sus scrofa. Hilar and interpulmonary communications were visualized in first 5 minutes post-inhalation, infradiaphragmatic chains between 10 and 20 minutes, the ganglia of the aortic chain at 20 minutes and those of the renal hilar region at 30 minutes. Conclusion the proposed method enables visualization of deep lymphatic lung network and lymph nodes. Besides, this technique involving the modulation of nanoradioliposomes targeting specific organs or tissues may be an important tool for diagnostic or even for therapeutic purposes.

Characterization and in vitro hemocompatibility of bi-soft segment, polycaprolactone-based poly(ester urethane urea) membranes.

In this study, surface, bulk, and hemocompatibility characteristics of crosslinked, bi-soft segment poly (ester urethane urea) membranes, prepared by extending a poly(propylene oxide)-based triisocyanate-terminated prepolymer (PU) with a polycaprolactone diol (PCL), were investigated. Variation of the ratio of PU to PCL diol content in the membrane formulation yielded alteration of surface energy, phase morphology both in the bulk and in the region near the surface, and it affected hemocompatibility. Nearly all membranes were nonhemolytic, with hemolysis degrees between 1 and 2.1% and, for short-time contact with blood (15 min), all membranes showed in vitro thrombosis degrees between 27 and 42%. The membranes prepared with 5 and 25% of PCL diol showed almost no adherent platelets. These two membranes had a higher hard segment aggregation in the region near the surface and mixing between the two soft segments in the bulk, but showed contrasting surface energy characteristics. The results obtained in this work give evidence that surface energy and its polar and dispersive components did not correlate with any of the hemocompatibility aspects studied. In contrast, the phase morphology in the region near the surface was a major influence on membrane hemocompatibility.

Prenatal administration of vitamin A alters pulmonary and plasma levels of vascular endothelial growth factor in the developing mouse

Vitamin A and the retinoids play a unique role in mammalian embryonic and foetal development and are essential for both cellular differentiation and the establishment of normal morphogenesis. Vascular endothelial growth factor (VEGF) is a known potent mitogenic factor that plays a key role in lung development and function maintenance. In order to contribute to a better knowledge of the modulating effects of vitamin A in lung development, we investigated the effects of the antenatal administration of vitamin A on VEGF expression in lungs and plasma from foetuses and neonates. Pregnant mice were subjected to subcutaneous administration of vitamin A on the 12th gestational day. The lungs and plasma from foetuses and neonates were collected daily from the 15th gestational day till the day of birth. Our results show that vitamin A modulates VEGF concentrations both in lungs and plasma. Statistically significant differences were observed at gestational days 15 (P = 0.004 for lungs; P < 0.0001 for plasma), 16 (P < 0.0001 for lungs and plasma) and 18 (P < 0.0001 for lungs; P < 0.05 for plasma). Vitamin A tends to increase the expression of this factor in the lung, particularly during the critical period of perinatal adaptation to postnatal life. These effects seem to be spatial and temporally regulated, and point out to the important role of vitamin A during lung development.

Immunocytochemical localization of endothelin-1 in human placenta from normal and preeclamptic pregnancies

OBJECTIVE The aim of this study was to examine the distribution of endothelin-1 (ET-1) in the human placenta at different gestational ages and to determine whether differences in ET-1 immunoreactivity occurred in preeclamptic compared with uncomplicated pregnancies. METHODS Localization of ET-1 was investigated by the immunoperoxidase technique in first-trimester, second-trimester, and term human placentas from normal pregnancies and in placentas from preeclamptic pregnancies. RESULTS In normal placentas from all gestational ages studied, endothelin-1 immunoreactivity (ET-1 IR) was specifically detected in the endothelium of the fetal vessels and in the syncytiotrophoblast. ET-1 IR was also expressed by the villous cytotrophoblast of first- and second-trimester normal placentas. The extravillous cytotrophoblast of the basal and chorionic plates also exhibited ET-1 IR, but with varying degrees of intensity. In preeclamptic placentas, the expression of ET-1 IR was uneven with a negative staining in all placentas from pregnancies between the 29th and 32nd weeks of gestation. The expression of ET-1 IR was most intense in some syncytiotrophoblast tissue in the terminal villi after the 33rd week of gestation. In placentas from preeclamptic pregnancies between the 35th and the 36th weeks of gestation, strong ET-1 IR expression was evident in the endothelium of fetal vessels and in the syncytiotrophoblast. Regardless of gestational age, ET-1 IR was also observed in the extravillous cytotrophoblast of the basal and chorionic plates of preeclamptic placentas. CONCLUSION This study demonstrates that ET-1 IR is widely distributed in the human placenta and provides further evidence to support the concept that ET-1 plays an important role as a modulator of vascular tone in the uteroplacental and fetoplacental units and may participate in the pathogenesis of preeclampsia.

Calcium stores in electropermeabilized HL-60 cells before and after differentiation

Non-induced HL-60 cells (N-IND) and HL-60 cells induced to differentiate with 2 microM retinoic acid (IND) were electropermeabilized with electrical discharges, and the intracellular Ca2+ stores were measured in each type of cell. Both N-IND and IND cells accumulate Ca2+ in the presence of ATP after electropermeabilization. The Ca2+ is stored in at least two different compartments; accumulation in one of the compartments is inhibited by oligomycin and CCCP, and it is not releasable by Ins(1,4,5)P3. The maximal accumulation of Ca2+ by the Ins(1,4,5)P3 sensitive pool is about 0.3 nmol/10(6) cells and 0.9 nmol/10(6) cells for the N-IND and for the IND cells, respectively, and the half-maximal value occurs at a free Ca2+ concentration of 0.23 microM and 0.63 microM, respectively. The oligomycin + CCCP sensitive pool hardly accumulates any Ca2+ at this level of free Ca2+, but at higher free [Ca2+] (greater than microM) its maximal capacity is 80-100-fold higher than the Ins(1,4,5)P3-sensitive pool (about 17-18 nmol/10(6) cells). It is concluded that at physiological free Ca2+ concentrations, the non-mitochondrial Ca2+ pool is regulating the intracellular free Ca2+ in N-IND and IND HL-60 cells, and that this Ca2+ pool can be mobilized by Ins(1,4,5)P3. Furthermore, the capacity of this pool increases about 3-fold when the cells are induced to differentiate with retinoic acid.

Nanorradiolipossomas modulados molecularmente para estudar a drenagem linfática pulmonar profunda

Resumo A drenagem linfatica pulmonar profunda (DLPP) desempenha um papel importante na remocao de materiais estranhos, constituindo os macrofagos alveolares a primeira linha de defesa fagocitaria, dada a grande afinidade para microrganismos patogenicos. Os Bacillus subtilis sao saprofitas do tracto respiratorio humano com ampla utilizacao em investigacao e em biotecnologia. As cadeias linfaticas pulmonares profundas (CLPP) constituem um dos primeiros locais de disseminacao de tumores pulmonares. Neste trabalho pretendeu-se desenvolver e validar um metodo nao invasivo para avaliar as CLPP atraves de nanorradiolipossomas aerosolisados e modulados pela parede do esporo do Bacillus subtilis . O objectivo final foi produzir uma formulacao de nanorradiolipossomas capaz de imitar a dinâmica da remocao de esporos pelas CLPP e simultaneamente ter propriedades ideais como tracador para imagiologia molecular. Testamos sete diferentes formulacoes lipossomicas, tendo a formulacao F demonstrado possuir propriedades fisicoquimicas e radiofarmaceuticas que a tornam o tracador ideal para imagiologia molecular in vivo das CLPP. Os nanorradiolipossomas da formulacao F apos marcacao com 99m Tc-HMPAO foram administrados sob a forma de aerossois a 20 Sus scrofa . Visualizaram-se comunicacoes hilares e interpulmonares nos primeiros 5 minutos apos a inalacao, as cadeias infradiafragmaticas entre os 10 e os 20 minutos, os gânglios da cadeia aortica aos 20 minutos e os da regiao hilar renal aos 30 minutos. Em conclusao, o metodo proposto visualiza os gânglios linfaticos e a rede linfatica pulmonar profunda. A modulacao dos nanorradiolipossomas permite que eles atinjam orgaos ou tecidos especificos, conferindo-lhes importantes potencialidades no âmbito do diagnostico e/ou da terapeutica. Rev Port Pneumol 2009; XV (2): 261-293

Quantification of Mouse Lung Elastin During Prenatal Development

Elastic fibres play a crucial function during the process of lung alveolisation. During the perinatal period, any changes in the elastogenic process during foetal development may result in permanent lifetime defects. In pre-natal life, well-developed pulmonary elastic fibres should favor the pre-natal maturation of the lung and an enhanced alveolisation, which in many species, such as humans begins only after birth. The authors present a quantitative study by image analysis and by high-pressure liquid chromatography (HPLC) of the mouse lungs’ elastic fibre content from the 15th till the 19th gestational day.

Quantification by Image Analysis of the Gallus gallus Lung Elastic Fibres from Embryonic to Adult Birds

The organization of the lungs elastic fibres is amazingly uniform in all vertebrates, with the possible exception of birds, whose pulmonary architecture and air movement are unique. The overall goal of this work was to study and quantify elastic fibre distribution patterns and relative amounts in the parabronchi, during the incubation period until the 42nd day after hatching. Chick embryo lungs were examined on the 14th, 16th, 18th and 20th days of incubation and chick lungs on the 1st, 2nd, 7th, 14th, 35th and 42nd days after hatching. Four animals were used daily, and the observations were randomly performed on both lungs. A morphometric study was carried out focusing on the computerized image analysis of histological sections stained according to a modified Gomori technique. The values obtained for each day result from the observation and processing of 20 images. Complementary studies were performed using transmission electron microscopy, as on the 14th embryonic day the fibres were not visible on light microscopy. The results show that the area occupied by the elastic fibres increases gradually from the 16th day of incubation up till the 7th day after hatching and decreases slowly in the following days of the study. A prominent increase takes place before hatching, which points out to the adequate and essential structural roles played by the elastic fibres in the pulmonary maturation process.

Elastic fibres in the human placenta.

Abstract. Recent studies described the presence of elastic fibres within stem villi of human term placenta. This particular study focuses on changes of the elastic fibre system in placental villous tree from placentas of different gestational ages. The presence of elastic fibres was researched by light and electron microscopy in first-, second-trimester and term human placentas. Light microscopic analysis revealed elastic fibres in the stroma of main stem villi and in large vessels present in the chorionic plate of term placentas. Transmission electron microscopy revealed a wide variation in microfibrillar component deposition in placentas from all the gestational ages studied. Although minimal amount of the microfibrillar component was observed only in some main stem villi of second-trimester placentas, abundant microfibrillar material was present in all types of placental villi in placental sections from term pregnancies. The amorphous component was only occasionally identified in sections from the chorionic plate of second trimester placentas. In ultra-thin sections from placental tissues from the 37th to the 42nd weeks of gestation, we can observe the amorphous component of the elastic fibres. Bundles of microfibrils with scanty participation of the amorphous component of the elastic fibres can be observed in stem villi. In mature intermediate villi, cells and their processes with distinct plasma membranes were seen close to some bundles of microfibrillar component, at times with small spots of the amorphous component. This study shows that elastic fibres of the villous stroma, are mainly composed of the microfibrillar component, while the amorphous component appears more frequently in advanced stages of villous differentiation of term placentas.