BPI-fold (BPIF) containing/plunc protein expression in human fetal major and minor salivary glands

Abstract The aim of this study was to determine expression, not previously described, of PLUNC (palate, lung, and nasal epithelium clone) (BPI-fold containing) proteins in major and minor salivary glands from very early fetal tissue to the end of the second trimester and thus gain further insight into the function of these proteins. Early fetal heads, and major and minor salivary glands were collected retrospectively and glands were classified according to morphodifferentiation stage. Expression of BPI-fold containing proteins was localized through immunohistochemistry. BPIFA2, the major BPI-fold containing protein in adult salivary glands, was detected only in the laryngeal pharynx; the lack of staining in salivary glands suggested salivary expression is either very late in development or is only in adult tissues. Early expression of BPIFA1 was seen in the trachea and nasal cavity with salivary gland expression only seen in late morphodifferentiation stages. BPIFB1 was seen in early neural tissue and at later stages in submandibular and sublingual glands. BPIFA1 is significantly expressed in early fetal oral tissue but BPIFB1 has extremely limited expression and the major salivary BPIF protein (BPIFA2) is not produced in fetal development. Further studies, with more sensitive techniques, will confirm the expression pattern and enable a better understanding of embryonic BPIF protein function.

Diagnóstico prenatal no invasivo: Ácidos nucleicos de origen fetal en sangre materna / Non invasive prenatal diagnosis: Fetal nucleic acid analysis in maternal blood

Las técnicas actuales de diagnóstico prenatal de enfermedades génicas y cromosómicas incluyen procedimientos invasivos que conllevan un pequeño, pero significativo, riesgo. Por muchos años se ha estudiado la posibilidad de utilizar células fetales en circulación materna; sin embargo, ha fracasado su implementación clínica debido a su escasez y persistencia luego del parto. Desde hace más de una década se detectó ADN fetal libre en sangre de embarazadas. Este sería de origen placentario e indetectable después del parto, y fuente de material fetal para el desarrollo de técnicas diagnósticas utilizando sangre materna. No obstante, la mayoría del ADN libre en circulación materna es de origen materno con una contribución fetal del 3% al 6% aumentando a lo largo de la gestación. Dado que los métodos actuales no permiten separar el ADN libre fetal del materno, las aplicaciones se focalizan en el análisis de genes no presentes en la madre, tales como secuencias del cromosoma Y, o gen RHD en madres Rh negativas, o mutaciones paternas o de novo. Asimismo, la detección de ARN fetal libre en sangre de embarazadas abrió la posibilidad de obtener información acerca de patrones de expresión génica de tejidos embrionarios y, utilizando genes que se expresan sólo en la unidad feto-placentaria, se podría establecer un control de presencia de material fetal, independiente del material genético de la madre. El presente trabajo describe las evidencias acerca del pasaje de ácidos nucleicos fetales a circulación materna, su aplicación actual en el diagnóstico prenatal y posibles usos futuros.

Current prenatal diagnosis of monogeneic and chromosomal diseases, includes invasive procedures which carry a small but significant risk. For many years, analysis of fetal cells in maternal circulation has been studied, however it has failed its clinical use due to the scarcity of these cells and their persistance after delivery. For more than a decade, the presence of cell-free fetal DNA in maternal blood has been identified. These fetal DNA fragments would derive from the placenta and are not detected after delivery, making them a source of fetal material for carrying out diagnosis techniques using maternal blood. However, the vast majority of cell free DNA in maternal circulation is of maternal origin, with the fetal component contributing from 3% to 6% and rising towards term. Available methodologies do not allow separation of fetal from maternal cell free DNA, so current applications have been focused on the analysis of genes not present in the mother, such as Y chromosome sequences, or RHD gene in RhD-negative women, or paternal or de novo mutations. Also, the detection of cell-free fetal RNA in maternal blood offers the possibility of obtaining information regarding genetic expression profiles of embrionic tissues, and using genes expressed only at the feto-placental unit, controls for the presence of fetal material could be established, regardless of maternal genetic tissue. The present article describes the evidences regarding the passage of fetal nucleic acids to maternal circulation, its current prenatal diagnosis application and possible future perspectives.

Differential expression of syntaxin-1 and synaptophysin in the developing and adult human retina.

Synaptophysin and syntaxin-1 are membrane proteins that associate with synaptic vesicles and presynaptic active zones at nerve endings, respectively. The former is known to be a good marker of synaptogenesis; this aspect, however, is not clear with syntaxin-1. In this study, the expression of both proteins was examined in the developing human retina and compared with their distribution in postnatal to adult retinas, by immunohistochemistry. In the inner plexiform layer, both were expressed simultaneously at 11-12 weeks of gestation, when synaptogenesis reportedly begins in the central retina. In the outer plexiform layer, however, the immunoreactivities were prominent by 16 weeks of gestation. Their expression in both plexiform layers followed a centre-to-periphery gradient. The immunoreactivities for both proteins were found in the immature photoreceptor, amacrine and ganglion cells; however, synaptophysin was differentially localized in bipolar cells and their axons, and syntaxin was present in some horizontal cells. In postnatal-to-adult retinas, synaptophysin immunoreactivity was prominent in photo-receptor terminals lying in the outer plexiform layer; on the contrary, syntaxin-1 was present in a thin immunoreactive band in this layer. In the inner plexiform layer, however, both were homogeneously distributed. Our study suggests that (i) syntaxin-1 appears in parallel with synapse formation; (ii) synaptogenesis in the human retina might follow a centre-to-periphery gradient; (iii) syntaxin-1 is likely to be absent from ribbon synapses of the outer plexiform layer, but may occur at presynaptic terminals of photoreceptor and horizontal cells, as is apparent from its localization in these cells, which is hitherto unreported for any vertebrate retina.

Diagnostico e terapia da hipoxia fetal durante o parto / Diagnosis and treatment of the intrapartum fetal hypoxia

Os autores discutem brevemente os mecanismos patofisiologicos das causas mais frequentes da hipoxia e acidose fetal intraparto, ou seja, a reducao da perfusao utero-placentaria e feto placentaria decorrentes principalmente da hiperatividade uterina e/ou compressao funicular. Tres metodos diagnosticos da hipoxia fetal intraparto sao abordados: a amnioscopia, cardiotocografia e a pHmetria do sangue no couro cabeludo fetal. Concluem que a pHmetria apresenta os melhores resultados em sensibilidade, especifidade e valores preditivos. O seu emprego na obstetricia atual e limitado pela falta de condicoes do seu uso de maneira continua, tornando-a um metodo complementar da cardiotocografia continua intraparto. E apresentado pelos autores um esquema de aplicacao pratica combinada dos tres metodos acima citados na vigilancia do bem estar fetal no trabalho de parto. A principal terapeutica da hipoxia fetal intraparto e a rapida interrupcao do parto, por intervencao obstetrica adequada ao periodo do trabalho de parto. Novos metodos como tocolise e amnioinfusao podem melhorar os resultados perinatais e ajudar a diminuir a incidencia de casareas.

Affinity chromatographic isolation of cell surface glycoproteins from human foetal brains and their interaction with lectins.

The cell surface glycoproteins of foetal human neurons and glial cells were isolated by affinity chromatography on Con A-Sepharose 4B. Dissociation of Con A from the matrix took place independent of buffer composition and the absence of lipids and/or detergents during chromatography. It was apparently related to the nature of glyco proteins. Pretreatment of Con A-Sepharose 4B with urea or guanidine minimized this problem. The elution of glycoproteins from the affinity matrix at 4 degrees C, instead of the usual 25 degrees C, reduced both Con A and glycolipid contamination in the eluate. Dot-enzyme-linked-lectin assay was carried out with horse radish peroxidase conjugated lectins and serotonin. It was observed that total glycoproteins contained high mannose, hybrid and a limited quantity of biantennary complex type oligosaccharide chains. O-linked oligosaccharides were also present. Desialylation and sodium chloride inhibited binding to serotonin and wheat germ agglutinin indicating the presence of sialic acid residues. Fucose was attached to the innermost core GlcNAc residue, as revealed by affinity towards pea lectin.