Fetal Connective Tissue Research Articles

Asymmetric growth-limiting development of the female conceptus.

Sex differences in prenatal growth may contribute to sex-dependent programming effects on postnatal phenotype. We integrated for the first time phenotypic, histomorphological, clinico-chemical, endocrine and gene expression analyses in a single species, the bovine conceptus at mid-gestation. We demonstrate that by mid-gestation, before the onset of accelerated growth, the female conceptus displays asymmetric lower growth compared to males. Female fetuses were smaller with lower ponderal index and organ weights than males. However, their brain:body weight, brain:liver weight and heart:body weight ratios were higher than in males, indicating brain and heart 'sparing'. The female placenta weighed less and had lower volumes of trophoblast and fetal connective tissue than the male placenta. Female umbilical cord vessel diameters were smaller, and female-specific relationships of body weight and brain:liver weight ratios with cord vessel diameters indicated that the umbilico-placental vascular system creates a growth-limiting environment where blood flow is redistributed to protect brain and heart growth. Clinico-chemical indicators of liver perfusion support this female-specific growth-limiting phenotype, while lower insulin-like growth factor 2 (IGF2) gene expression in brain and heart, and lower circulating IGF2, implicate female-specific modulation of key endocrine mediators by nutrient supply. This mode of female development may increase resilience to environmental perturbations in utero and contribute to sex-bias in programming outcomes including susceptibility to non-communicable diseases.

Histo-morphometric vicissitudes in diet-controlled diabetic placenta: A quantitative stereological model

BackgroundAn affordable approach accepted worldwide to successfully treat mild maternal hyperglycemia in gestational diabetes (GDM), is diet-controlled therapy. As no elaborate research was available, this study was crafted to investigate morphometric stereological details and to determine the mean placental oxygen diffusion capacity for patients who were kept on diet therapy for mild gestational hyperglycemia. MethodsA clinical trial (NCT04907708) was conducted from January 2018 to February 2019. A total of 70 women completed the study, out of which 35 served as healthy controls as Group A and 35 were diagnosed as mild gestational diabetics according to WHO criteria (Group B). These patients were kept on a restricted calorie diet with light exercise during gestation and were followed regularly during gestation. Soon after delivery, conserved placentas underwent complete gross, microscopic, and stereological investigations with the point and intersection -counting methods. ResultsSignificant differences were observed for placental width and syncytial knots (p＜ ​0.010 and 0.025 respectively) between the groups on gross and light microscopy. Most of the parameters were non-significant, though numerically more in the GDM group. On stereological details, mean placental volume, mean placental components volumes (villi, inter-villous space, fetal capillary, and fetal connective tissue), mean villi and mean fetal capillary diameter, mean villi and capillary surface density and mean morphometric diffusing capacity of placenta showed non-significant results between the groups. ConclusionMinimal changes were observed in gross, microscopy, and morphometric stereological details in the placentae of GDM patients managed with nutritional therapy during gestation compared with the healthy controls.

Fetal Stem Cells Use as Antiaging and Rejuvenation Strategies

Objectives: Our goal was to refine upon the methods of treatment and rejuvenation by way of combination including classical treatment and fetal stem cells (FSCs) administered in suspensions containing fetal liver cells, cells of fetal brain as well as fetal connective tissue. Materials and methods: 126 persons were involved into our study divided into 2 groups: the patients of the 1st group (67 persons including 40 women of average age 42.35 ± 0.78 and 27 men of mean age 44.16 ± 0.69 years) were administered FSCs during 3 days. Suspensions of fetal liver were administered (2 to 5 mL per 200.0 mL saline solution) for 60 min on treatment day 1. Treatment day 2 suggested use of suspensions of FSCs extracted from placenta from 4 to 6 mL s.c. injected to the anterior abdominal wall. Suspensions containing connective tissue cells administered in the anterior abdominal wall (2.5 to 4 mL). The patients of the 2nd group (59 persons under study, including 28 women of average age 43.21 ± 0.81 years and 31 men of mean age by 42.21 ± 0.72 years) were additionally performed cosmetology procedures in the region of face and decollete with application of chorion extract onto provisionally prepared facial skin in volume of 2 mL, followed by plotting with special thermo-mask on the face. Results: The authors proved effectiveness and safety of treatment by FSCs in persons undergoing therapy for rejuvenation. Significant improvement of hormonal status and levels of electrolytes was recorded under this study. In the 2nd group esthetician noticed a significant improvement of skin in the region of face and decollete already over 3 months after FSCs administration. Conclusion: FSCs use in complex treatment of patients as antiaging and rejuvenation strategies improves hormonal background and skin general appearance in the region of face and decollete.

Histomorphometric parameters of normal full term placenta of Sudanese women.

The aim of the study was to provide values for morphometric parameters of histological components of normally delivered full term placentas of Sudanese women and compare them with reported parameters for other ethnic groups. A total of 200 histological sections, stained with hematoxylin and eosin and trichrome stains were used to give a final sample of 1000 fields saved as PowerPoint images for histomorphometry. A systematic random sampling procedure was adopted to ensure the optimum sample size that keeps the percentage error below 5% for the volume estimates. Standard stereological methods of point-counting and intersection-counting were applied to the microscopic fields to determine the volumes of placental components and surface area of fetal-maternal interface. The morphometric parameters showed no variations either between the placentas or between central and peripheral regions. The placental villi and the intervillus space occupied 65% and 35% of placental volume respectively with mean absolute values of 318 cm3 and 169 cm3. The mean absolute volume of the intervillus space was less than that of other ethnic groups by 8.67% but was significantly larger than that of the fetal capillaries which measured 41.2 cm3. The ratio of the absolute volume of the intervillus space to the volume of the fetal blood capillaries was 4:1 in both Sudanese and other ethnic groups. In the placental villi the fetal connective tissue together with the contained blood vessels larger than capillaries occupied 88% of the villus volume. The mean surface area of the fetal-maternal interface of the placental villi (syncytiotrophoblast) was 12.59 M2.

Steroid and xenobiotic receptor-mediated effects of bisphenol A on human osteoblasts

Bisphenol A, one of the industrial chemicals used in plastics and in the coating of dishes and medical equipment, behaves as an endocrine disruptor in the human body. Bisphenol A can bind directly to several types of nuclear receptors, including steroid and xenobiotic receptor (SXR). SXR plays an important role in bone metabolism through the activation of osteoblasts in vitro, but SXR protein localization has not been reported in bone tissues. Additionally, it is not known whether bisphenol A acts on osteoblasts through SXR activation. Therefore, in this study, we first examined the immunolocalization of the SXR protein in human adult and fetal bone tissues. We then examined the effects of bisphenol A on human osteoblasts in vitro. SXR immunoreactivity was detected in osteoblasts, but not in osteoclasts, of both adult and fetal bone tissues. In fetal bone tissues, the mesenchymal cells or fetal connective tissue were also positive for SXR immunoreactivity. Expression of SXR target genes (tsukushi, matrilin-2, and CYP3A4) and SXR response element-luciferase activity were increased by bisphenol A treatment in normal osteoblasts transfected with SXR (hFOB/SXR) and in osteoblast-like cells (MG-63). Bisphenol A also stimulated cell proliferation and collagen accumulation in hFOB/SXR cells. These results suggest that, as in other tissues, SXR plays important roles in bone metabolism and fetal bone development and that bisphenol A may disturb bone homeostasis in both adult and fetus through SXR.

Food allergens are transferred intact across the rat blood-placental barrier in vivo

We investigated the mechanism of transplacental macromolecular transport in rats on the nineteenth day of pregnancy using tracers, transmission electron microscopy and immunohistochemistry. The blood-placental barrier of full-term rat placentas was composed of a trilaminar layer of trophoblast cells that separates the fetal capillaries from the maternal blood spaces: a layer of cytotrophoblasts lining the maternal blood space and a bilayer of syncytiotrophoblast surrounding the fetal capillaries. Horseradish peroxidase, intravenously injected into the maternal circulation, was found in the maternal blood spaces, the interspaces between the cytotrophoblasts and the syncytiotrophoblast I, many pits and small vesicles in the syncytiotrophoblast I, vesicles of the syncytiotrophoblast II, fetal connective tissue and fetal capillaries. Intravenously injected ovalbumin was detected in the maternal blood spaces, a trilaminar layer and the fetal capillaries. Neonatal Fc receptor (FcRn), a receptor for IgG, was localized at the maternal side of the blood-placental barrier. These results show that the structure of the rat blood-placental barrier is quite similar to the human blood-placental barrier, and non-specific macromolecules and food allergens may penetrate through the blood-placental barrier of the full-term placenta from the maternal to fetal circulation mediated by FcRn.

Características histomorfométricas do placentomo de vacas Nelore nos terços inicial, médio e final de gestação

Avaliaram-se as características histomorfométricas do placentomo da vaca Nelore nos terços inicial, médio e final da gestação utilizando-se 52 úteros gestantes. Para a estimativa do estádio gestacional, foram utilizados aspectos do desenvolvimento fetal. Foram coletados fragmentos de um placentomo localizado no corno uterino ipsilateral ao corpo lúteo, os quais foram imersos em solução de formol e, posteriormente, processados histologicamente, incluídos em parafina e corados com hematoxilina-eosina. O estudo das proporções volumétricas foi feito utilizando-se microscópio de luz equipado com ocular integradora. Foi feita, também, a quantificação das células epiteliais nas criptas das carúnculas por meio de microscopia de luz e uma ocular micrométrica com 100 divisões. Foi verificado decréscimo no número das células maternas do epitélio das criptas no final da gestação. Os números médios das células binucleadas do trofoblasto, nos terços inicial, médio e final da gestação, mantiveram-se semelhantes, bem como a proporção volumétrica dos componentes dos tecidos conjuntivos materno e fetal e dos vasos no tecido materno. No tecido fetal, ocorreu aumento gradativo do tecido conjuntivo nos terços inicial, médio e final

COMPARATIVE MORPHOLOGICAL FEATURES OF THE PLACENTAL BARRIER AND LOCALIZATION OF ESTROGEN RECEPTORS α IN THE PLACENTA OF COWS AND BUFFALOES

The present study was conducted to identify the morphological characteristics of the placental barrier and localization of estrogen receptors α in the cow and buffalo placentas. Placentomes were collected from 3 pregnant cows and 3 pregnant buffaloes at the 5th and 6th months of gestation respectively. The placentomes were fixed by using 10% neutral buffered formalin for immunohistochimestry and were post fixed in 3% glutaraldehyde for light microscopy. Indirect immunoperoxidase staining methods using monoclonal antibody against bovine ERα as primary antibody was applied. The morphometric data were obtained by using Q500 MC Image processing and analysis program. Histological examination revealed that there is a great similarity in the structure of the placental barrier of cows and buffaloes, whereas typical six slayers of tissue were seen separating the fetal blood from the maternal one. These layers were maternal endothelium, thin layer of maternal connective tissue, maternal uterine epithelial cells, fetal trophoblast cells, fetal connective tissue and fetal endothelium. Nuclear immunoreactivities occurred mainly in the maternal crypt epithelium and maternal connective tissue cells. In about 1000 maternal uterine cryptal cells, 87.6% were positive cells for ERα in the cow placenta and about 67.8% were positive cells in the buffalo placenta. The present study concluded that although there is a great similarity in the structure of the placental barrier and expression of ERα in the placentas of cows and buffaloes interbreeding between the two species is impossible due to the different number of chromosomes set. The placenta of cows seems to be less responsive to estrogen in comparison to that of buffaloes.

282 CHARACTERIZATION OF THE DEVELOPMENTAL POTENTIAL OF FETAL SOMATIC STEM CELLS ISOLATED FROM DIFFERENT TISSUES

Recently we discovered a novel type of stem cells which can be derived from primary cultures of fetal connective tissue using a high-density culture (HD) system (Kues et al. 2005 Biol. Reprod. 70, 1020–1028). This cell type shows most of the characteristics of true embryonic stem cells and is a promising alternative for developing therapeutically useful cells. The goal of the present study was to analyze and characterize stem cell populations obtained from five different tissues, i.e., brain, heart, lung, liver, and adrenal gland, using this HD culture system. Explant cultures of the double transgenic strain OG2/Rosa26 were established from mouse fetuses at Day 13.5 post-conception. In this strain, cells with pluripotent properties are characterized by the green fluorescence of the green fluorescent protein (GFP) which is under the transcriptional control of the Oct-4 promoter. In a total of five replicates, cells were subcultivated and reseeded at a concentration of 25 000 cells/cm–2. Cell culture conditions were as recently reported for fetal somatic stem cell derivation (Kues et al. 2005 Biol. Reprod. 72, 1020–1028). After colony formation and/or observation of green fluorescence under UV illumination, mRNA was isolated for RT-PCR analysis of the expression of genes known to be involved in pluripotency, i.e., Oct-4, Nanog, Stat3, TNAP, Rex1, and Sox2. Under these culture conditions, 12.5% of the liver and 80% of the brain explants showed senescence and could not be seeded at the required concentration. No colony formation was observed in brain and heart cultures. Cells from heart explants showed a three-dimensional growth over the whole surface of the attached cells and were difficult to separate. On average, colony formation was observed after 11 days � 8 (mean � SD) (fetal fibroblasts), 10 days � 7 (lung), 18 days � 11 (liver), and 4 days � 1 (adrenal gland). Green fluorescence was detected after 17 days � 9 (fetal fibroblasts), 17 days � 9 (lung), 35 days � 13 (heart, randomly distributed), 26 days � 10 (brain), 26 days � 8 (liver), and 8 days � 5 (adrenal gland). A single large clump of stem-like cells formed in 43% of the fetal fibroblast, 35% of the lung, and 41% of the liver derivatives. Oct-4 expression was not observed in any of the cultures. Nanog and Stat3 were expressed in all cell cultures, and TNAP was expressed in all cultures from heart, brain, lung, and adrenal gland. Rex1 was expressed in all cultures from brain and adrenal gland, and in 25% of the heart cultures and in 16.6% of the fetal fibroblasts. Sox2 was expressed in all cultures from brain and in 16.6% of fetal fibroblast cultures. These preliminary results show that cells with some of the typical features of stem cells can be derived from various tissues of the body, but that the efficiency is different among tissues. Only cells derived from the adrenal gland exhibited better colony formation than the original fibroblasts. This work was funded by DFG grant Ni 256/28-1.

The Epithelial Layer of the Term Placenta of the Asian Elephant (Elephas maximus): a Light and Scanning Electron Microscopic Study

This combined light and scanning electron microscopic (SEM) analyses are the first investigation of the fine morphology of the fetal membranes of the placenta in the Asian elephant. We used two term placentas with gestation periods of 634 days (Zoological Garden Leipzig) and 657 days (Zoo Hagenbeck) and selected unequal sites as specimens, particularly ‐ free membrane of the allantois, ‐ lateral edge of the placenta band, the ‘haemophagous zone’, ‐ allantochorion near the placental band, and allantochorion on the end of the chorioallantoic sac. Microscopically the free membrane of the allantois shows a simple, cuboidal epithelium with apical domains of microplicae and microvilli (fig. 1, inset). In the SEM analyses we documented a cobblestone‐like architecture of the epithelial cells with various cell sizes, small, middle and giant (fig. 1.). Furthermore, we found pear‐shaped cells with long pedicle, attached to the basement membrane and cell openings, presumably due to cell desquamation (fig. 2.). The haemophagous zone was characterized with a lamellate system between the long finger‐like chorionic villi and the maternal blood lacunae. The simple, squamous and columnar trophoblast cells are here bathed in the maternal blood. In some chorionic villi brown‐yellow material is deposited in the fetal connective tissue. A special result was the presence of strip‐like microplicae in the middle of chorionic villi. The allantochorion near the placental band sometimes indicated simple and ramified chorionic villi with smooth, gyrus‐like trophoblast cells and foamy cytoplasm. The attached allantois possesses a simple, columnar epithelium with microvilli. Furthermore, we observed villi‐like projections rising up to the allantoic cavity. The white ‘pustules’ on the outer surface of the end of the chorioallantoic sac consist of stratified squamous epithelia. Numerous mitoses were documentedin the basal domain of the pustules. A surprisingly result was the presence of intra‐epithelial capillaries. They invade the trophoblast cells to presume a nutrient exchange also outside of the placental band with its important functional metabolism. This study revealed unknown and interesting features of the epithelial layer of different locations in the placenta of the Asian elephant. Perhaps, with a detailed knowledge of the morphology of the epithelium we could convey a better understanding of functional cohesions of elephant placentation. image [ The free membranes of the allantois of the term placenta of the Asian elephant (Elephas maximus) shows a cobblestone‐like architecture of the simple cuboidal epithelial cells with various sizes. The surface morphology was determined through microplicae and microvilli. ] image [ Numerous pear‐shaped cells with long pedicle exist among the cuboidal epithelial cells, attached on the basement membrane. The cells possessed modifications of their surface, particularly microplicae. Some pear‐shaped cells shows only the pedicle, perhaps that is a loss through preparation or its presumable due to cell desquamation. One erythrocyte is localized between these cells. ]

Immunohistochemical assessment of progesterone, oestrogen and glucocorticoid receptors in bovine placentomes during pregnancy, induced parturition, and after birth with or without retention of fetal membranes

Steroid hormones play an important role in placental development. However, the exact cellular site of hormone action has not been evaluated in bovine placentomes. Thus, the present immunohistochemical study was designed to assess the distribution of progesterone receptors, oestrogen receptors and glucocorticoid receptors in bovine placentomes. Tissue specimens were obtained from cows at slaughter and from cattle during pre-term Caesarean section 27 h after prostaglandin administration, immediately after spontaneous parturition and from cattle that had retained the fetal membranes. Specific antibodies were used for receptor demonstration in tissue sections. Progesterone receptors were only detected in maternal connective tissue cells, whereas oestrogen receptors were also present in maternal crypt epithelium. At specific sites, both receptor immunoreactivities remained constant or changed significantly during pregnancy, were generally higher during Caesarean section and decreased post partum, but were less pronounced in cattle that released the fetal membranes than in those that retained the fetal membranes. Glucocorticoid receptors were evident in fetal connective tissue cells as well as in fetal and maternal blood vessels. Maternal crypt epithelial cells showed increasing immunoreactivities for glucocorticoid receptors during pregnancy. Receptor immunoreactivities tended to be lower after spontaneous parturition than during Caesarean section; these results were significant for progesterone and oestrogen receptors in animals that released the fetal membranes but not for those that retained the fetal membranes. The results indicate that in bovine placentome steroid hormone receptors are distributed in patterns that are specific to the type of cell, the stage of pregnancy and the tissue location, implying highly specific modulation of placental metabolism. Retention of the fetal membranes is reflected by altered placental receptor states at parturition.

Immunohistochemical assessment of progesterone, oestrogen and glucocorticoid receptors in bovine placentomes during pregnancy, induced parturition, and after birth with or without retention of fetal membranes

Steroid hormones play an important role in placental development. However, the exact cellular site of hormone action has not been evaluated in bovine placentomes. Thus, the present immunohistochemical study was designed to assess the distribution of progesterone receptors, oestrogen receptors and glucocorticoid receptors in bovine placentomes. Tissue specimens were obtained from cows at slaughter and from cattle during pre-term Caesarean section 27 h after prostaglandin administration, immediately after spontaneous parturition and from cattle that had retained the fetal membranes. Specific antibodies were used for receptor demonstration in tissue sections. Progesterone receptors were only detected in maternal connective tissue cells, whereas oestrogen receptors were also present in maternal crypt epithelium. At specific sites, both receptor immunoreactivities remained constant or changed significantly during pregnancy, were generally higher during Caesarean section and decreased post partum, but were less pronounced in cattle that released the fetal membranes than in those that retained the fetal membranes. Glucocorticoid receptors were evident in fetal connective tissue cells as well as in fetal and maternal blood vessels. Maternal crypt epithelial cells showed increasing immunoreactivities for glucocorticoid receptors during pregnancy. Receptor immunoreactivities tended to be lower after spontaneous parturition than during Caesarean section; these results were significant for progesterone and oestrogen receptors in animals that released the fetal membranes but not for those that retained the fetal membranes. The results indicate that in bovine placentome steroid hormone receptors are distributed in patterns that are specific to the type of cell, the stage of pregnancy and the tissue location, implying highly specific modulation of placental metabolism. Retention of the fetal membranes is reflected by altered placental receptor states at parturition.

Placental histology in twin-twin transfusion syndrome (TTTS) in the mouse

Summary The structure of monochorionic twin placentae with and without twin-twin transfusion syndrome (TTTS) was studied in mice at 17 days gestation. The TTTS donor showed anemia and growth retardation, while the TTTS recipient evidenced polycythemia and active secretion of amniotic fluid. The histological architecture of the donor placental labyrinth in TTTS showed a failure of the labyrinth to develop and immature trophoblast cells. Fetal connective tissue spaces were extensive, but no blood vessels developed there. In the TTTS recipient, the placental labyrinth developed well. Further studies are needed to establish what appears to be a promising model for human TTTS.

Immunohistological examination on the distribution of collagen types I, III, IV and V in bovine post partum placentomes.

This paper describes the in situ presence and distribution of collagen types I, III, IV and V in the bovine placenta. The objective was to determine whether there are qualitative and/or quantitative differences in the collagen content of placentomes originating from cows with retained placenta and cows with normal discharge of placenta. Twelve h post partum discharge of the placenta or the incidence of retained placenta was monitored. From 57 cows one placentome per cow was collected within 1 h post partum. The cows were divided into three groups: retained placenta after caesarean section (Group 1), retained placenta after spontaneous calving (Group 2) and normal discharge of placenta within 12 h post partum after spontaneous calving (Group 3). A pilot study was conducted to establish the technique of collecting the placentomes and to verify the applied immunohistological methods used in this work. In the following study, 32 placentomes were used to determine the amount of collagen (types I, III, IV and V) with qualitative and semi-quantitative methods using immunohistochemical techniques. Collagen types I, III, IV and V were found in large quantities in the maternal tissue. In the fetal connective tissue the amount of these collagen types was smaller. In the placentomes of the three groups, no qualitative or quantitative differences could be detected.

Volumetric proportions of the goat placenta structural components throughout gestation

The goal of this research was to determine the volumetric proportions of the structural components of the goat placenta throughout gestation. We used nine goats of nondefined breed, separated into groups A, B and C, with 90, 120 and 150 days of gestation, respectively. From each animal fragments of three placentomes were obtained, one removed from the base, another from the middle part and the other from the end of the gestational uterine horn. The fragments were fixed in Bouin solution and histologically processed according to the standard techniques and stained with hematoxilin-eosin. Microscopically, a 25-point circular grid (Zeiss KPL ocular 6.3x with 25 points) was randomly used across the placentome to determine the volumetric proportion of the maternal and fetal connective tissue, syncytium, trophoblastic epithelium and binucleate cells. An increase of volumetric proportion of the syncytium was found at the end of gestation and also a decrease of volumetric proportion of fetal connective tissue in the same period.

Ovine placenta related to binucleated cells in fetal membrane retention

Placentomes were collected from 28 Iraqi Awassi ewes which had retained their fetal membranes after; (a) normal birth ( n = 6); (b) abortion ( n = 6), (c) dystocia ( n = 10), and (d) Caesarean section ( n = 6). Histologic changes in placentomes obtained from ewes with retained fetal membranes (RFM) after normal birth included vascular changes (edema, hyperemia and hemorrhages), hemosiderin pigmentation, necrosis in the maternal villi and presence of moderate to large numbers of binucleate cells (BNC). In placentomes obtained from ewes having RFM after abortion, there were vascular changes in both maternal and fetal connective tissues. Necrosis and massive bacterial colonies were seen in the caruncles and cotyledons. Few numbers of BNC and infiltration of polymorphonuclear and mononuclear cells in the caruncles and cotyledons were observed. The changes in placentomes obtained from ewes having RFM after dystocia (treated by assisted delivery) included the presence of vascular changes, hemosiderin pigmentation, moderate degree of necrosis and few bacterial colonies in the caruncles and cotyledons. Moderate numbers of BNC were observed. On the other hand, in cases of dystocia (treated with a Caesarean section), vascular changes, moderate degrees of necrosis and few numbers of bacterial colonies were observed in caruncles and cotyledons and only few BNC. It was concluded that BNC are involved in the process of placental separation in ewes.

205 HYALURONAN AND WATER CONTENT IN THE LUNG OF PRETERM AND TERM INFANTS WHO DIED LESS THAN 24 HOURS AFTER BIRTH

Fetal connective tissue is known to have a very high concentration of hyaluronan (HA) and of water. In rabbit pups the concentration of HA in the lung has its lowest value one day before term gestation (Am J Physiol 260, 1449, 1991). After birth an increase in lung HA is accompanied by an increase in lung water (Ped Res 1992;32: 635& 1994;35:280).AIM: To determine the concentration of HA and water in the lung of infants who died less than 24 hours after birth.RESULTS: The HA concentration in the lungs of infants born after 23-27 gestational weeks (g.w.)ranged between 1030-2832 μg/g dry lung weight(n=8) and in those born after 2 28 g.w. between 374-1875 μg/g(n=21). The relation between HA concentration and gestational age seemed exponential. Lung water content was high in all infants. HA staining in lung structures was more widely spread in very preterm than in more mature infants. A subepithelial lining of HA could be seen in moderately preterm infants.CONCLUSION: The concentration of hyaluronan in the lungs of newborn infants decreased with increasing gestational age at births. The water content of thp lungs of all infants in this study was high.

Localization of epidermal growth factor receptors in first- and third-trimester human placentas.

Studies to date have demonstrated epidermal growth factor (EGF) receptors primarily on the outer plasma membrane of the human placental syncytiotrophoblasts facing maternal blood and to a lesser extent on the cytotrophoblast stem cells. In the present studies, first- and third-trimester human placental tissues were immunostained with monoclonal antibodies (MAb) to the EGF binding domain of the human EGF receptor or to the activated (tyrosine-phosphorylated) human EGF receptor. Cytotrophoblasts, syncytiotrophoblasts, and fetal connective tissue cells in first-trimester tissues immunostained with both MAb, with the notable exception of the absence of staining of activated EGF receptor over cytotrophoblast plasma membranes. In contrast, staining of third-trimester placentas with either MAb yielded little to no staining of either trophoblast cell layer but intense staining of fetal connective tissue cells. Staining for EGF receptors over cytotrophoblasts in the first trimester is consistent with the hypothesis that maternal EGF or TGF-alpha derived from the endometrium or placenta may be the mitogen responsible for cytotrophoblast cell division and that the receptors localized to the syncytiotrophoblast are involved in EGF regulation of differentiated function. The absence of heavy staining of activated EGF receptor on trophoblast plasma membranes in third-trimester placentas is consistent with down-regulation of EGF receptor activity.

In situ demonstration and characterization of progonadotropin-releasing hormone messenger ribonucleic acid in first trimester human placentas

GnRH has been shown to play a role in the regulation of secretion of hCG by human placenta. Immunocytochemical studies have demonstrated the presence of the peptide, but do not address whether the GnRH is maternal, fetal, or placental in origin. In situ hybridization studies using a biotinylated pro-GnRH cDNA were, therefore, undertaken to determine the distribution of pro-GnRH mRNA in first trimester placental samples. Using an avidin-biotin-Cy.5 detection system in conjunction with laser scanning confocal microscopy, pro-GnRH mRNA was shown to be present in both the cytotrophoblast and syncytiotrophoblast cells of placental villi, although not in the cells of the fetal connective tissue. Prior hybridization with a 200-fold excess of unlabeled probe blocked hybridization of the labeled pro-GnRH probe. Southern and sequence analysis demonstrated that the probe hybridized to a transcript identical to hypothalamic GnRH. Immunocytochemical staining using an antiserum to amino acids 6-16 of pro-GnRH demonstrated the presence of translated pro-GnRH in both the cytotrophoblast and syncytiotrophoblast epithelia. We conclude that the synthesis of pro-GnRH by both the cytotrophoblast and the syncytiotrophoblast of human placenta is consistent with either an autocrine or a paracrine mode of GnRH regulation of hCG secretion.

In situ demonstration and characterization of progonadotropin-releasing hormone messenger ribonucleic acid in first trimester human placentas.

GnRH has been shown to play a role in the regulation of secretion of hCG by human placenta. Immunocytochemical studies have demonstrated the presence of the peptide, but do not address whether the GnRH is maternal, fetal, or placental in origin. In situ hybridization studies using a biotinylated pro-GnRH cDNA were, therefore, undertaken to determine the distribution of pro-GnRH mRNA in first trimester placental samples. Using an avidin-biotin-Cy.5 detection system in conjunction with laser scanning confocal microscopy, pro-GnRH mRNA was shown to be present in both the cytotrophoblast and syncytiotrophoblast cells of placental villi, although not in the cells of the fetal connective tissue. Prior hybridization with a 200-fold excess of unlabeled probe blocked hybridization of the labeled pro-GnRH probe. Southern and sequence analysis demonstrated that the probe hybridized to a transcript identical to hypothalamic GnRH. Immunocytochemical staining using an antiserum to amino acids 6-16 of pro-GnRH demonstrated the presence of translated pro-GnRH in both the cytotrophoblast and syncytiotrophoblast epithelia. We conclude that the synthesis of pro-GnRH by both the cytotrophoblast and the syncytiotrophoblast of human placenta is consistent with either an autocrine or a paracrine mode of GnRH regulation of hCG secretion.