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Biomedical subjects

M A Miglino

Publications and source records attributed to M A Miglino.

At least 19 recordsLinked to original sources
PubMed2006

Culture of mature trophoblastic giant cells from bovine placentomes.

The mostly binucleate trophoblast giant cells (TGC) found in bovine placentomes, in addition to synthesizing and releasing hormones play an important role in fetal development and maternal adaptation to pregnancy. Placentomes from early gestation were collected, and for isolation of mature TGC, three cellular disaggregation methods, mechanical (MECH), enzymatic by trypsin (TRYP) or collagenase (COLL) were compared to each other. Further on, the cell survival in culture medium (DMEM) supplemented with either 10% fetal calf serum (FCS) or 10% serum replacement (SR) on culture plates free of any substrate was evaluated over a period of 90 days by trypan blue exclusion. The cells were further characterized by HOECHST 33342 nuclear staining, and immunocytochemical staining with monoclonal antibodies against vimentin and cytokeratin. A mean total rate of TGC survival of 82.56% was recorded. Statistical analysis showed significantly higher survival rates after enzymatic disaggregation with COLL (86.23%) than following MECH (80.38%) or TRYP (80.91%) treatment. Supplementation of DMEM with FCS resulted in significantly higher cellular survival rates (87.13%) when compared to the addition of SR (77.73%). Analysis of the influence of both, disaggregation method and medium supplementation on TGC survival revealed statistically significant differences between the following groups: MECH-SR (71.09%) was significantly lower than all other groups; TRYP-SR (78.03%) was significantly different from all other groups; TRYP-FCS (83.43%) and COLL-SR (84.08%) were significantly lower than MECH-FCS (89.98%) which together with COLL-FCS (88.25%) showed the highest cellular survival rate. In summary, our results show that TGC isolated from early gestation placentomes may be viable for more than 90 days of culture. However, whether these TGC produce placental lactogen throughout this period has yet to be determined.

Animals↗
PubMed2006

Binucleate trophoblast giant cells in the water buffalo (Bubalus bubalis) placenta.

The binucleate trophoblast giant cells (BNC) of the water buffalo, Bubalus bubalis, placenta were studied, with emphasis on the synthesis of BNC-specific proteins. Placentomal tissues of 27 water buffalos (2-10 months of pregnancy) were processed for light and electron microscopy. The frequency of BNCs was 20% of the trophoblastic cells in 2-3-month placentas and increased to 27% in the later stages. Ultrastructurally, binucleate cells displayed a prominent granular endoplasmic reticulum and Golgi apparatus, typical of cells involved with protein synthesis and exportation. The buffalo BNCs contained periodic acid-Schiff (PAS)-positive granules and reacted with antisera against bovine placental lactogen, prolactin-related protein-I, and pregnancy-associated glycoproteins. Lectin histochemistry with Dolichos biflorus agglutinin, Vicia villosa agglutinin, and Phaseolus vulgaris leucoagglutinin showed specific staining of BNCs. Different stages of BNC migration and fusion with uterine epithelial cells were observed. Trinucleate feto-maternal hybrid cells were the typical outcome of cell fusions. These cells underwent degeneration, with typical morphological features of apoptosis. The results revealed a strong homology between water buffalo and cattle BNCs concerning cell morphology, protein expression, glycosylation pattern, and characteristics of cell migration and fusion.

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PubMed2006

Placentation in the rock cavy, Kerodon rupestris (Wied).

Rock cavies are rodents found in the semi-arid caatinga of Brazil. We studied the structure of the rock cavy placenta by light and transmission electron microscopy. The exchange area of the labyrinth was organized in lobes separated by interlobular areas. The interhaemal barrier was syncytial haemomonochorial. The syncytiotrophoblast had recesses in the basal membrane and some invaginations of the apical membrane, but transtrophoblastic channels could not be found. The interlobular regions comprised syncytiotrophoblast, enclosing maternal venous blood channels, and cytotrophoblast. There was a prominent subplacenta composed of cytotrophoblast and syncytiotrophoblast. Microvilli projected into spaces between the cytotrophoblasts and into lacunae within the syncytiotrophoblast. The yolk sac epithelium exhibited coated pits, endocytotic vesicles and larger vacuoles, consistent with a role in protein uptake from the uterine lumen. Tight junctions between these cells provided a barrier to diffusion by the intercellular route. The reproductive biology of the rock cavy differs from other members of the family, including the guinea pig, but the architecture of the placenta remains remarkably constant.

Amnion↗
PubMed2004

Vascular organization of the hystricomorph placenta: a comparative study in the agouti, capybara, guinea pig, paca and rock cavy.

The placental vasculature of five hystricomorph rodents was examined by latex injection of the blood vessels, immunohistochemistry and scanning electron microscopy of vessel casts. The pattern of branching of the vessels is described at the level of fine structure. The placenta is divided into lobes separated by interlobular trophoblast. Fetal arteries course through the interlobular areas and give rise to capillaries from which blood drains into veins at the centre of the lobes. Maternal blood reaches the placenta through spiral arteries that pass around the perimeter of the subplacenta. They supply large maternal blood sinuses, lined by trophoblast, which run through the interlobular areas and into the centre of the lobes. Here they supply fine channels that run parallel to the fetal capillaries, so that maternal blood flows from the centre of the lobe to the periphery. This arrangement provides the morphological basis for countercurrent exchange. The maternal channels of the labyrinth drain into spaces formed by the latticework of the interlobular trophoblast and thence through venous lacunae to a basal venous lacunar ring. The subplacenta is supplied by a single fetal artery. The vessels within the subplacenta pursue a tortuous course with dilatations and constrictions as in an endocrine gland.

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PubMed2004

Placental glycosylation in peccary species and its relation to that of swine and dromedary.

Comparison has been made between glycans at the fetomaternal interface of two Tayassu species (New World peccaries or wild pigs) and those of swine (true pigs) and dromedary, which have similar epitheliochorial placentae. Plastic sections of near-term fetomaternal interface from Tayassu tajacu (120 days gestation) and Tayassu pecari (140 days gestation) were stained with 20 lectins and compared with those of swine (109 days) and dromedary (375 days). Both Tayassu species showed similar staining characteristics, which differed only slightly from those of the swine. Most differences were quantitative rather than qualitative, except for binding of Arachis hypogaea lectin to terminal beta-galactose which was absent in swine uterine epithelium though present in both Tayassu species, and binding of Sambucus nigra lectin to sialic acid which was absent in swine epithelium and trophoblast though present in Tayassu. Glycosylation of the dromedary fetomaternal interface showed, in contrast, significant differences compared to Tayassu and swine, particularly regarding fucosyl, sialyl and terminal galactosyl residues. Despite a divergence of between 33 million and 37 million years between true pigs and peccaries, glycosylation of the fetomaternal interface has remained similar, with most of the observed changes affecting terminal structures. The dromedary has an epitheliochorial placenta with a similar architecture, but different glycan expression, suggesting modification of glycosyl transferases with evolution. These data contain clues to changes of glycosyl transferase activity that accompany speciation.

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PubMed2002

Placentation in the capybara (Hydrochaerus hydrochaeris), Agouti (Dasyprocta aguti) and paca (Agouti paca).

Placentae of three hystricimorph rodents--capybara, agouti and paca--were examined by conventional histology, immunohistochemistry for cytokeratin and vimentin, and TUNEL staining. The placentae were divided into lobules of labyrinthine syncytium separated by interlobular and marginal trophoblast. The subplacenta comprised cytotrophoblasts, supported on lamellae of allantoic mesoderm, and syncytiotrophoblast. The central excavation was still apparent in the definitive placenta of capybara. In agouti and paca, the decidua of the junctional zone formed a mesoplacenta comprising a capsule and a pedicle. Towards term the pedicle formed a tenuous attachment between placenta and uterine wall comprising a few maternal vessels surrounded by degraded tissue. In paca placenta, it was shown by TUNEL staining that breakdown of this tissue occurred by apoptosis. The visceral yolk sac was highly villous and, in agouti, the yolk sac villi were extremely long. Lateral to its attachment to the placenta, the fetal surface was covered with non-vascular yolk sac endoderm. A layer of spongiotrophoblast cells was interposed between the endoderm and the marginal trophoblast.

Animals↗
PubMed2001

The three-dimensional feto-maternal vascular interrelationship during early bovine placental development: a scanning electron microscopical study.

Both the fetal and maternal microvasculature of bovine placentomes was examined by scanning electron microscopy of vascular casts. So far the development of the vascular architecture of the bovine placentome in early gestation has only been studied 2-dimensionally due to technical difficulties arising from the fragility of the early placental blood vessels. Repeated experiments led to the selection of the microvascular corrosion casts presented here. The vasculature of the maternal compartment is supplied by large caruncular stalk or spiral arteries, which release short maternal stem arteries. In the 3rd month of gestation, these arteries branch into several arterioles at their base, thus providing the vascular framework for the lower part of the septal walls of the primary crypts. In the 4th month, due to progressive longitudinal growth of the stem arteries, branching into arterioles occurs not only at the base, but over the whole length of the stem arteries. These arterioles supply the capillary complexes of the septa which resemble the major part of the septal vasculature and face the secondary crypts. Further indentation results in the formation of tertiary crypt capillary complexes, encircling the earlier secondary unit. From the 6th month of gestation the architecture resembles the fully developed maternal placenta with stem arteries running directly to the fetal side to branch into 4 to 6 arterioles, which turn back to enter secondary and tertiary septa. Maternal venules, collecting the blood from the capillary bed of secondary and tertiary septa, converge onto stem veins leaving the caruncle via branches of the uterine vein. The fetal part of the placentome is supplied by the cotyledonary arteries, which branch into fetal stem arteries that are the tributary to single villous trees. Over their whole course towards the maternal side, these give off arterioles entering secondary villi. The tertiary or terminal villous vasculature consists of capillaries, which are organised in serial capillary loops. This system is progressively elaborated in the course of gestation. In the 4th month there are only finger-like loops, whereas from the 6th month large fan-like structures can be observed. In early gestation the maternal and fetal blood vessels meet predominantly in a countercurrent fashion, changing to the less efficient crosscurrent exchange when the tertiary unit develops. These results indicate the development of a highly elaborated fetomaternal villous-crypt exchange system, already established in the 1st half of gestation, thus meeting the increasing needs of the fetus.

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PubMed1997

Morphology of the swine ileum terminale.

The morphology of the terminal ileum was studied in 33 male adult pigs of unknown breed. The ileum ended in the cecocolic junction at an acute angle to the cecum. The terminal ileum displayed a cylindrical form (63.6% +/- 8.4 of the cases) more frequently than an ampullary (21.2% +/- 7.1) and/or an infundibular form (15.2% +/- 6.2). The ampullary form is not related to the quadrupedal position of the animal, but is related to the functional phase of the intestine at the time of death. In the mucous tunica of the terminal ileum, longitudinal folds and aggregated lymphoid nodules appeared concentrated along the antimesenteric border.

Animals↗
PubMed1993

Subcellular organization of the placenta in the Atlantic sharpnose shark, Rhizoprionodon terraenovae.

The Atlantic sharpnose shark, Rhizoprionodon terraenovae, is a viviparous anamniote that develops a yolk sac placenta composed of: a) uterine mucosa, b) egg envelope and c) fetal yolk sac mucosa. The transporting uterine mucosa is a squamous epithelial bilayer with prominent lateral and basal infoldings between contiguous cells. The surface cells have prominent secretion vesicles that empty their contents to the exterior. Immediately beneath the epithelium is a basal lamina and a profuse vascular supply with a continuous endothelium. The epithelium of paraplacental uterine sites is mucous. The tertiary egg envelope is retained throughout gestation and separates the distal part of the yolk sac from the maternal uterine mucosa. The egg envelope is compact on the yolk sac surface but displays delaminations on the uterine surface. The fetal yolk sac is composed of two portions, viz., a proximal, saccular region and a heavily vascularized, rugose, distal portion. The proximal portion has ultrastructural characteristics of a steroid hormone producing tissue, including massive smooth endoplasmic reticulum frequently forming whorled arrays. However, definitive evidence that the yolk sac is an endocrine organ is lacking. The distal portion of the fetal yolk sac is composed of a squamous epithelial bilayer that is separated from the underlying vascular network by a continuous basal lamina. The endothelium of the vessels is fenestrated. Cytoplasmic characteristics of these cells include an extensive Golgi complex, smooth walled caveolae, vesicles with electron-dense contents that are presumably endocytotic in nature and dense bodies that are suggested to be lysosomes that are involved in the digestion of material that may be yolk metabolites.

Amnion↗
PubMed1993

Fine structure of the term umbilical cord in the Atlantic sharpnose shark, Rhizoprionodon terraenovae.

The fine structure of the umbilical cord and appendiculae in the Atlantic sharpnose shark, Rhizoprionodon terraenovae, is examined by light, scanning and transmission electron microscopy. During ontogeny of placental sharks, the yolk sac and stalk become progressively modified as a functional hematrophic placenta and umbilical cord respectively. In most placental sharks the umbilical cord is smooth. In the Atlantic sharpnose shark, the epithelial ectoderm of the somatopleure forms richly vascularized extensions termed appendiculae. Scanning electron microscopy reveals that the base and shaft of appendiculae are flattened while the distal portion may be expanded to form one to three lobes. The surface of appendiculae is composed of two distinct cell types, the most plentiful are microvillar cells. The second cell type contains prominent granules. These cells are much larger than the former and are partially submerged below the surface, except for the cell apex. These cells undergo secretory cycles ending in expulsion of their contents. The possible function of the granulated cells is discussed. The umbilical cord contains an umbilical vein, umbilical artery, ductus vitellointestinalis and extraembryonic coelom. The endodermal ductus initially conveys yolk from the yolk sac to the fetal gut by activity of ciliated cells lining it. The ductus persists in the adult. Microvillar cells, also present in the ductus, may play a role in the absorption of yolk metabolites early in development, prior to yolk depletion. Enteroendocrine cells are wedged between the ciliated and microvillar cells. These cells may exert paracrine regulation of local areas of the ductus.

Animals↗
PubMed1991

Atrioventricular and ventriculoatrial branches of the coronary arteries in human hearts.

Atrioventricular (AV) and ventriculoatrial (VA) branches of the coronary arteries are vessels which supply simultaneously atrial and ventricular walls by means of recurrent rami. The terminology indicates the name of the main vessel followed by the name of the recurrent vessel both combined in an adjective. These branches establish a vascular 'suture' across the coronary sulcus in front (superficially to) or behind (deeply to) the trunks of the right coronary artery and of the left coronary artery (circumflex artery). The AV and VA branches, found in 95% of 40 human hearts, should be considered a normal characteristic of the coronary circulation and an important anatomical factor for the clinical interpretation of pathological cardiac phenomena.

Adult↗
PubMed1991

[Topography of the blood vessels in the hilum of the kidney of Myrmecophaga tridactyla].

The study was undertaken in 10 formol-imbibed kidneys of great anteater (Myrmecophaga tridactyla). After the dissection the following characteristics were showed: kidney blood vessels are distributed in 2 different sites, namely hilar and extrahilar, amounting 3 to 6 in the right side 3 to 7 in the left side. Arterial branches in extrahilar region range from 1 to 2 in both sides and in hilar region they present from 1 to 4 in the right and 1 to 2 in the left. Venous roots occur in 1 to 2 vessels in the right and 1 to 3 vessels in the left, occupying only the hilar region, except one case where it was present in the right side.

Animals↗
PubMed1983

The gallbladder of the Capivara Hydrochoerus hydrochoeris (Mammalia: Rodentia).

The authors studied morphological and histochemically the mucopolysaccharides and proteins in the gallbladder tubular glands and epithelial cells of the capivara Hydrochoerus hydrochoeris. Based on the results the authors concluded: 1. the gallbladder single columnar epithelium consists of secretory, migrating, and goblet cells; 2. in the lamina propria are single coiled tubular glands; 3. goblet and tubular gland cells show neutral and sulphated mucopolysaccharides and sialic acid; 4. columnar cells show neutral mucopolysaccharides and protein radicals; 5. migrating cells show only protein radicals.

Animals↗
PubMedDate not supplied

Macroscopic and microscopic aspects of collared peccary and white-lipped peccary placenta.

This study examines middle and late gestational placentae from 13 Tayassu tajacu (collared peccary) and 3 Tayassu pecari (white-lipped peccary), which are Artiodactyla belonging to the Family Tayassuidae. The chorionic sac of Tayassu species is diffuse and chorioallantoic. These epitheliochorial placentae show no trophoblast invasion into the uterine epithelium and there is interdigitation between fetal and maternal microvilli. Two distinct regions of the fetomaternal interface can be identified: the interareolar and the areolar regions. The uterine epithelium has eosinophilic cytoplasm with dispersed, basophilic and electron-dense granules. Trophoblast cells are irregularly cuboidal on top of the fetal ridges and columnar on troughs, where cells have cytoplasmic vesicles and large basal vacuoles, surrounded by whorls of smooth membranes. Capillaries indent the trophoblast cells forming a placental barrier 3 microm or less thick. The columnar uterine glandular epithelium has a subpopulation of granules staining with Perl's Prussian blue reaction, suggesting iron secretion. In areolar areas, the trophoblast cells show apical microvilli, a basophilic cytoplasm with electron-dense intracellular vacuoles and cisternae. The placenta can therefore be classified as non-deciduate. The ultrastructural aspects of this study reveal features that have not previously been described and extend our knowledge of functions relating to materno-fetal transport in these species.

Animals↗
PubMedDate not supplied

Morphological study of the vas deferens of the pigeon (Columba livia).

A morphological study of the vas deferens of the pigeon was carried out in order to determine the electronmicroscopic features of its epithelial lining, and the expression of pancytokeratins. The results showed that the epithelium is columnar pseudostratified and consists of non-ciliated (principal) cells and basal cells. Presence of a predominantly granular endoplasmic reticulum, mitochondria and well-developed Golgi complexes bearing vesicles on their cis/trans surfaces were observed. In addition to these vesicles associated with the Golgi complexes were observed membrane-delimited vesicles with a low electron density content or with an electrondense content mainly related to the endoplasmic reticulum. Apical cytoplasmic expansions with heterogeneous cytoplasmic content were also seen. These subcellular features associated to the presence of pancytokeratins, suggest the occurrence of a secretory process in principal cells, as well provide a mural structural support to the vas deferens.

Animals↗
PubMedDate not supplied

History of the anatomy of the funiculus umbilicalis in mammals.

The authors, based on a bibliographic search, present a brief survey of the history of the anatomical aspects of the funiculus in mammals, including the evolution of their interpretation and their relationship with the evolution of scientific and technological approaches to their study.

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