Covid-19 vaccination in pregnancy and placental pathology

Objective:To describe and determine the association between Covid-19 vaccination in pregnancy and placental pathology.Methods:Conducted in a tertiary hospital in Medan,Indonesia,from April 30th 2022 to June 30th 2022,this single-center cross-sectional study involved Covid-19 vaccinated and unvaccinated women with singleton full-term pregnancies delivering live fetuses via cesarean section.Maternal characteristics,placental pathologies,and the placental index were documented at enrollment.The association between Covid-19 vaccination status and placental pathology was assessed.Results:The study enrolled 200 pregnant women,including 110 vaccinated women and 90 unvaccinated women.No significant differences were observed in birthweight(P=0.48),placental index(P=0.48),and placental pathology findings[intervillous bleeding(P=0.20),increased syncytial knots(P=0.83),chorangiosis(P=0.13),villous stromal edema(P=0.13),vascular dilation and congestion(P=0.13),and vascular wall thrombus(P=0.71)]between the vaccinated and unvaccinated groups.Conclusions:This study revealed no statistically significant association between Covid-19 vaccination and placental pathology.The findings support the safety of Covid-19 vaccination during pregnancy,in regards to changes of the placental pathology.

Spatially resolved transcriptomic profiling of placental development in dairy cow

The placenta plays a crucial role in successful mammalian reproduction.Ruminant animals possess a semi-invasive placenta characterized by a highly vascularized structure formed by maternal endometrial caruncles and fetal placental cotyledons,essential for full-term fetal development.The cow placenta harbors at least two trophoblast cell populations:uninucleate(UNC)and binucleate(BNC)cells.However,the limited capacity to elucidate the transcriptomic dynamics of the placental natural environment has resulted in a poor understanding of both the molecular and cellular interactions between trophoblast cells and niches,and the molecular mechanisms governing trophoblast differentiation and functionalization.To fill this knowledge gap,we employed Stereo-seq to map spatial gene expression patterns at near single-cell resolution in the cow placenta at 90 and 130 days of gestation,attaining high-resolution,spatially resolved gene expression profiles.Based on clustering and cell marker gene expression analyses,key transcription factors,including YBX1 and NPAS2,were shown to regulate the heterogeneity of trophoblast cell subpopulations.Cell communication and trajectory analysis provided a framework for understanding cell-cell interactions and the differentiation of trophoblasts into BNCs in the placental microenvironment.Differential analysis of cell trajectories identified a set of genes involved in regulation of trophoblast differentiation.Additionally,spatial modules and co-variant genes that help shape specific tissue structures were identified.Together,these findings provide foundational insights into important biological pathways critical to the placental development and function in cows.

Maternal supplementation with n-3 fatty acids affects placental lipid metabolism, inflammation, oxidative stress, the endocannabinoid system, and the neonate cytokine concentrations in dairy cows

Background The placenta plays a crucial role in supporting and influencing fetal development.We compared the effects of prepartum supplementation with omega-3(n-3)fatty acid(FA)sources,flaxseed oil(FLX)and fish oil(FO),on the expression of genes and proteins related to lipid metabolism,inflammation,oxidative stress,and the endocannabinoid system(ECS)in the expelled placenta,as well as on FA profile and inflammatory response of neonates.Late-pregnant Holstein dairy cows were supplemented with saturated fat(CTL),FLX,or FO.Placental cotyledons(n=5)were collected immediately after expulsion,and extracted RNA and proteins were analyzed by RTPCR and proteomic analysis.Neonatal blood was assessed for FA composition and concentrations of inflammatory markers.Results FO increased the gene expression of fatty acid binding protein 4(FABP4),interleukin 10(IL-10),catalase(CAT),cannabinoid receptor 1(CNR1),and cannabinoid receptor 2(CNR2)compared with CTL placenta.Gene expression of ECS-enzyme FA-amide hydrolase(FAAH)was lower in FLX and FO than in CTL.Proteomic analysis identified 3,974 proteins;of these,51–59 were differentially abundant between treatments(P≤0.05,|fold change|≥1.5).Top canonical pathways enriched in FLX vs.CTL and in FO vs.CTL were triglyceride metabolism and inflammatory processes.Both n-3 FA increased the placental abundance of FA binding proteins(FABPs)3 and 7.The abundance of CNR1 cannabinoid-receptor-interacting-protein-1(CNRIP1)was reduced in FO vs.FLX.In silico modeling affirmed that bovine FABPs bind to endocannabinoids.The FLX increased the abundance of inflammatory CD44-antigen and secreted-phosphoprotein-1,whereas prostaglandin-endoperoxide synthase 2 was decreased in FO vs.CTL placenta.Maternal FO enriched neonatal plasma with n-3 FAs,and both FLX and FO reduced interleukin-6 concentrations compared with CTL.Conclusion Maternal n-3 FA from FLX and FO differentially affected the bovine placenta;both enhanced lipid metabolism and modulated oxidative stress,however,FO increased some transcriptional ECS components,possibly related to the increased FABPs.Maternal FO induced a unique balance of pro-and anti-inflammatory components in the placenta.Taken together,different sources of n-3 FA during late pregnancy enhanced placental immune and metabolic processes,which may affect the neonatal immune system.

The Hidden Side of the Story between the Placenta and Preeclampsia: Preliminary Results of a Prospective Cohort of Pregnant Women in Cameroon

Introduction: Pre-eclampsia is a complication of pregnancy that generally occurs in the third trimester. It is associated with a maternal and foetal mortality rate of around 27%. In view of the grim picture painted by this condition for both mother and newborn, studies have been carried out into the early detection of patients at risk of developing pre-eclampsia. These make it possible to introduce pregnancy-specific monitoring and preventive strategies to reduce the incidence of the condition. Objective: To establish the link between placental ultrasound characteristics and the onset of pre-eclampsia. Methodology: A multicentre prospective cohort study was conducted in two hospitals in Yaoundé, namely the Yaoundé Gynaecological Obstetrics and Paediatrics Hospital and the Nkolndongo Health and Social Animation Centre, in the gynaecology and radiology departments over a period of 11 months, from October 2022 to August 2023. It included pregnant women who had undergone obstetric ultrasound between 12 and 18 weeks’ gestation. In addition to routine obstetric ultrasound, we performed obstetric Doppler measurements in these patients. The resistance index of the left and right uterine arteries, the umbilical artery and the placental volume were the characteristics sought. At the end of this examination, two groups were formed: cases (pathological Doppler group) and controls (normal Doppler group). Blood pressure and urine dipstick were taken at each antenatal visit until delivery, then during the immediate postpartum period and finally at 7 days, 21 days and 42 days after delivery. Results: Sixty-seven (67) patients were included. Of these, 35 (47.8%) had pathological Dopplers. Sixteen patients had arterial hypertension associated with proteinuria and were therefore labelled as pre-eclampsia (PE). This gives a prevalence of 23.9%. Fifteen (42.8%) of these patients belonged to the exposed group and one to the unexposed group. The mean IR of the pre-eclampsia patients was significantly higher than that of the patients without pre-eclampsia;respectively 0.74 ± 0.096 and 0.49 ± 0.097 for the right uterine arteries and 0.71 ± 0.13 and 0.52 ± 0.089 for the left uterine arteries. We found that an increase in the uterine artery resistance index was significantly associated with the onset of pre-eclampsia, with a relative risk of 13.7 and a p value Conclusion: Abnormal Doppler ultrasound between 12 and 18 weeks of amenorrhoea had good overall sensitivity for predicting pre-eclampsia. Among the Doppler indices, the uterine artery resistance index was the only one significantly associated with pre-eclampsia.

Effect of Yizhikang Powder on Hemorheological Indexes in Dairy Cattle with Retained Placenta

[ Objective ] The aim of the research was to reveal the mechanism of Yizhikang powder treatment on dairy cattle with retained placenta from the hemorheological perspective. [ Method] Dairy cattle with retained placenta were treated with oral administration of Yizhikang powder. And their hemorheological indexes were measured and compared with the corresponding indicators of pre-administration group, healthy group, and control group （sick but untreated）.[ Result] There was large decrease amplitude in the indexes （whole blood viscosity, plasma viscosity, whole blood viscosity reduction viscosity, ESR, ESR equation K value, fibrinogen content, platelet aggregation rate, RBC deformability IF value） of treated dairy cattle with retained placenta. By t test, the indexes, except hematocrit, decreased significantly after treatment （P〈0.05） and reached the status of post partum healthy cows. The hemorheological indexes didn＇t change significantly in the control group before and after treatment. [ Conclusion] Yizhikang powder could significantly improve blood flow state and reduced the occurrence of qi stagnation and blood stasis in perinatal period.

Determination and Analysis on Nutritional Components in Placenta of Plateau Yak

Yaks live in Qinghai-Tibet Plateau （4 km above sea level）, and the nutrient components of their placenta were determined, including 17 kinds of amino acids and 11 kinds of trace elements. The results showed that there are abundant amino acids and trace elements in the placenta of yak, equal to that of human and deer, indicating some medical and nutritional value of yak placenta.

Dietary resveratrol improves antioxidant status of sows and piglets and regulates antioxidant gene expression in placenta by Keap1-Nrf2 pathway and Sirt1

Background: Resveratrol, a plant phenol, affords protection against inflammation and oxidative stress. The objective of this study was to investigate the effects of dietary resveratrol supplementation during pregnancy and lactation on the antioxidant status of sows and piglets and on antioxidant gene expression and pathway in placenta.Methods: Forty sows were allotted to 2 dietary treatments 20 d after breeding. Sows were fed a control diet and a control diet with 300 mg/kg resveratrol. Oxidative stress biomarkers and antioxidant enzymes were measured in the placenta, milk, and plasma of sows and piglets. Antioxidant gene expression and protein expression of Kelch-like ECH-associated protein 1-Nuclear factor E2-related factor 2(Keap1-Nrf2), nuclear factor kappa B-p65(NFκB-p65) and sirtuin1(Sirt1) were quantified in the placenta.Results: Dietary resveratrol increased the litter and piglets weaning weights. Antioxidant status in the milk, placenta and plasma of sows and piglets was partially improved by dietary resveratrol. In placenta, Nrf2 protein expression was increased and Keap1 protein expression was decreased by dietary resveratrol. The m RNA expression of antioxidant genes including catalase(CAT), glutathione peroxidase 1(GPX1), GPX4, superoxide dismutase 1(SOD1)and heme oxygenase 1(HO1), and phase 2 detoxification genes, including glutamate-cysteine ligase modifier(GCLM), microsomal glutathione S-transferase 1(MGST1) and UDP glucuronosyltransferase family 1 member A1(UGT1 A1), was increased by dietary resveratrol. Dietary resveratrol also increased Sirt1 and phosphorylated NFκB-p65 protein expression in the placenta. We failed to observe any influences of dietary resveratrol on pro-inflammatory cytokine levels, including those of interleukin 1β(IL-1β), IL-6, IL-8 and tumor necrosis factor α(TNF-α). However, we observed that the m RNA expression of IL-8 in placenta was reduced by maternal resveratrol. In addition, dietary resveratrol showed interactive effects with day of lactation on activities of SOD and CAT and levels of malonaldehyde(MDA) and hydrogen peroxide(H2 O2) in milk.Conclusions: Dietary resveratrol supplementation during pregnancy and lactation improves the antioxidant status of sows and piglets, which is beneficial to the reproductive performance of sows. Dietary resveratrol regulates placental antioxidant gene expression by the Keap1-Nrf2 pathway and Sirt1 in placenta.

Uterine Artery Embolization for Management of Primary Postpartum Hemorrhage Associated with Placenta Accreta

Objective To evaluate the efficacy and safety of uterine artery embolization(UAE) in the management of primary postpartum hemorrhage associated with placenta accreta. Methods We retrospectively reviewed the medical records of patients with placenta accreta between January 2010 and August 2014. Totally 18 women(mean age 30.8±4.2 years) of primary massive postpartum hemorrhage with diagnosis of placenta accrete received treatment of UAE after delivery. Images of DSA and medical records were reviewed. Technical success was defined as control of bleeding after embolization. The complications, control of hemorrhage and recurrent bleeding of the placenta left inside the uterus were retrospectively collected for assessment. Results All patients underwent transcatheter embolization of bilateral uterine arteries. The technical success rate of embolization was 100%. Bleeding was controlled in 17 of 18 patients(94%) during follow-up period(median 18 months, 3-31months) without further bleeding recurred. One patient with placenta percreta undertook an emergent hysterectomy along with surgical bladder repair after UAE because of persistent uterine bleeding. Eight patients had postembolization syndrome and no other complications occurred. Conclusion Uterine artery embolization is an effective and safe treatment for the management of primary postpartum massive hemorrhage associated with placenta accreta.

Relationship between Placenta Location and Resolution of Second Trimester Placenta Previa

This prospective study was conducted to assess the rate of resolution of second trimester placenta previa in women with anterior placenta and posterior placenta, and that in women with and without previous cesarean section. In this study, placenta previa was defined as a placenta lying within 20 mm of the internal cervical os or overlapping it. We recruited 183 women diagnosed with previa between 20+0 weeks and 25+6 weeks. They were grouped according to their placenta location(anterior or posterior) and history of cesarean section. Comparative analysis was performed on demographic data, resolution rate of previa and pregnancy outcomes between anterior group and posterior group, and on those between cesarean section group and non-cesarean section group. Women with an anterior placenta tended to be advanced in parity(P=0.040) and have increased number of dilatation and curettage(P=0.044). The women in cesarean section group were significantly older(P=0.000) and had more parity(P=0.000), gravidity(P=0.000), and dilatation and curettage(P=0.048) than in non-cesarean section group. Resolution of previa at delivery occurred in 87.43% women in this study. Women with a posterior placenta had a higher rate of resolution(P=0.030), while history of cesarean section made no difference. Gestational age at resolution was earlier in posterior group(P=0.002) and non-cesarean section group(P=0.008) than in anterior group and cesarean section group correspondingly. Placenta location and prior cesarean section did not influence obstetric outcomes and neonatal outcomes. This study indicates that it is more likely to have subsequent resolution of the previa when the placenta is posteriorly located for women who are diagnosed with placenta previa in the second trimester.

Placental-derived stem cells:Culture, differentiation and challenges

Stem cell therapy is a promising approach to clinical healing in several diseases. A great variety of tissues(bone marrow, adipose tissue, and placenta) arepotentially sources of stem cells. Placenta-derived stem cells(p-SCs) are in between embryonic and mesenchymal stem cells, sharing characteristics with both, such as non-carcinogenic status and property to differentiate in all embryonic germ layers. Moreover, their use is not ethically restricted as fetal membranes are considered medical waste after birth. In this context, the present review will be focused on the biological properties, culture and potential cell therapy uses of placental-derived stem cells. Immunophenotype characterization, mainly for surface marker expression, and basic principles of p-SC isolation and culture(mechanical separation or enzymatic digestion of the tissues, the most used culture media, cell plating conditions) will be presented. In addition, some preclinical studies that were performed in different medical areas will be cited, focusing on neurological, liver, pancreatic, heart, muscle, pulmonary, and bone diseases and also in tissue engineering field. Finally, some challenges for stem cell therapy applications will be highlighted. The understanding of the mechanisms involved in the p-SCs differentiation and the achievement of pure cell populations(after differentiation) are key points that must be clarified before bringing the preclinical studies, performed at the bench, to the medical practice.

Implication of Expression of Osteopontin and Its Receptor Integrin αvβ3 in the Placenta in the Development of Preeclampsia

To investigate the expression of osteopontin （OPN） and its receptor integrin αvβ3 in the placental tissue from pregnant women complicated with preeclampsia, the expression of OPN and αvβ3 in the placenta of the pregnant women with preeclampsia and healthy pregnant women was detected by immunohistochemistry, Western blotting and RT-PCR. Our results showed that OPN and αvβ3 protein were expressed in the placenta from normal pregnant woman and those with preeclampsia. OPN was located in the placental syncytiotrophoblasts and the cytoplasm of capillary endothelial cells and integrin αvβ3 was mainly expressed on the surface of trophoblast cells. Expression of OPN and integrin αvβ3 in the placental tissue from preeclampsia subjects was significantly lower than that from the control group （P〈0.05）. Compared with the control group, expression of OPN in the placental tissue from preeclampsia group was significantly lower （P〈0.05） but there was no significant difference in the expression of αv and β3 between the preeclampsia group and the controls. It is concluded that OPN and its receptor integrin αvβ3 may be involved in the pathogenesis of preeclampsia.

Placental accommodations for transport and metabolism during intra-uterine crowding in pigs

Litter size and birth weights are limited by uterine capacity, defined as the ability of the uterus to maintain the appropriate development of some number of conceptuses. Uterine capacity is the result of the combined effects of uterine, placental and embryo/fetal function. The number of living conceptuses that the uterus is capable of supporting is greater during early gestation compared to later gestation. Plots of log fetal weight versus log placental weight also indicate that fetal weights are less sensitive to reduced placental weight （and therefore reduced intrauterine space） in early gestation compared to late gestation. However, even in late gestation, mechanisms still exist that maintain fetal growth when the size of the placenta is reduced. One such mechanism is likely to be improved development of the folded placental-epithelial/maternal-epithelial bilayer. Fold depth, and therefore the maternal fetal interactive surface, increases as gestation advances and is greater in placenta from smal fetuses. On the fetal side of the placenta, the epithelial bilayer is embedded in stromal tissue. Glycosaminoglycans are major components of stroma, including hyaluronan and heparan sulfate. Hyaluronidases and heparanases are present within placental tissues, and likely play roles in modification of stromal components to facilitate fold development. Glycosaminoglycans are polymers of forms of glucose （glucosamine, glucuronic acid, iduronic acid） suggesting that glycosaminoglycan synthesis may compete with the glucose needs of the developing fetus. Pig conceptuses are fructogenic, such that a substantial portion of glucose transferred from mother to fetus is converted to fructose. Fructose is an intermediate product in the synthesis of glucosamine from glucose, and glucosamine is linked to regulation of trophoblast cell proliferation through regulation of mTOR. These findings suggest a link between glucose, fructose, glucosamine synthesis, GAG production, and placental morphogenesis, but the details of these interactions remain unclear. In addition, recent placental epithelial transcriptome analysis identified several glucose, amino acid, lipid, vitamin, mineral and hormone transporter mechanisms within the placenta. Further elucidation of mechanisms of placental morphogenesis and solute transport could provide clues to improving nutrient transport to the pig fetus, potentially increasing litter size and piglet birth weights.

Assessment of the Number and Function of Macrophages in the Placenta of Gestational Diabetes Mellitus Patients

In order to assess the number and function of macrophages in the placenta of pregnancy complicated with gestational diabetes mellitus （GDM） as well as those of normal pregnancies, placenta samples were collected from 15 GDM patients （GDM group） and 10 normal pregnant women （control group）. The expression levels of macrophage markers （CD68/CD14） and inflammatory cytokines （IL-6/TNF-α） in placenta were detected using immunohistochemistry and PCR. The results showed that the number of CD68＋ or CD14＋ cells in the GMD group was remarkably higher than that in the control group （P〈0.05）, indicating that the number of macrophages in the GDM group was significantly greater than that in the control group. The mRNA expression levels of CD68＋, IL-6 and TNF-α were higher in the GMD group than in the control group. In conclusion, more macrophages accumulate in placenta of pregnancy complicated with GDM, and the expression levels of pro-inflammation factors are also in- creased in GDM pregnancies, suggesting that macrophages and inflammatory mediators （IL-6 and TNF-α） mav olav an imoortant role in GDM.

Application of abdominal aortic balloon occlusion followed by uterine artery embolization for the treatment of pernicious placenta previa complicated with placenta accreta during cesarean section

Objective:This study aimed to investigate the clinical effects of abdominal aortic balloon occlusion followed by uterine artery embolization for the treatment of pernicious placenta previa complicated with placenta accreta during cesarean section.Methods:We performed a retrospective analysis of the clinical data for 623 patients who experienced pernicious placenta previa complicated with placenta accreta and received treatment in our hospital from January 2013 to January 2019.All patients underwent abdominal aortic balloon occlusion before their cesarean section.Seventyeight patients received bilateral uterine artery embolization,and among them,placenta accreta was found at the opening of the cervix in 13 patients.Due to suturing difficulty after the removal of the placenta,gauze packing was used to temporarily compress the hemorrhage.As soon as the uterus was sutured,emergent bilateral uterine artery embolization was performed.Active bleeding was noted in the remaining 65 patients when the lower part of the uterus was pressed after the placenta was removed and the uterus was sutured,therefor,bilateral uterine artery embolization was performed urgently.Results:Of the 623 patients,545 patients underwent only abdominal aortic balloon occlusion and 78 patients underwent additional emergent bilateral uterine artery embolization due to hemorrhaging during or after their cesarean section.No hysterectomies were performed.In the 78 patients,the amount of bleeding was 800-3,200 ml with an average of 1,650 ml during the operation;the volume of blood transfused was 360-1,750 ml(average:960 ml).The fetal fluoroscopy time was 3–8 s(average:5 s).The dose of radiation exposure was(4.2±2.9) m Gy.Fetal appearance,pulse,grimace,activity,and respiration(Apgar) score were normal.No serious complications were observed during or after the operation in the follow-up visits.Conclusion:For patients with pernicious placenta previa complicated with placenta accreta who experience active bleeding after cesarean section and abdominal aortic balloon occlusion,bilateral uterine artery embolization can effectively reduce blood loss and requirement of blood transfusion during the operation,and lowers the risk of hysterectomy.

Risk Factors and Pregnancy Outcomes： Complete versus Incomplete Placenta Previa in Mid-pregnancy

This prospective study was conducted to compare risk factors and pregnancy outcomes between women with complete placenta previa and those with incomplete placenta previa diagnosed in mid-pregnancy. The study was carried out from April 2014 to December 2015, during which 70 patients with complete previa and 113 with incomplete previa between 20＋0 weeks and 25＋6 weeks of gestation were included. Maternal demographics and pregnancy outcomes were compared between the two groups. Comparisons between categorical variables were tested by chi-squared test and those between continuous variables by Student t test. Resolution ofprevia occurred in 87.43% of the studied women. The mean gestational age at resolution was 32.1＋4.4 weeks. Incidence of maternal age ≥35 years and incidence of prior uterine operation 〉3 were high in women with complete previa （28.6% vs. 8.8%, P=0.003; 28.6% vs. 8.8%, P=0.003）. Resolution ofprevia occurred less often in complete previa group （74.3% vs. 95.6%, P=0.001）. Women with complete previa admitted earlier （37.3±2.0 weeks vs. 38.1±1.4 weeks, P=0.011） and delivered earlier （37.7±1.2 weeks vs. 38.3±1.4 weeks, P=0.025）. Maternal age ≥35 years and prior uterine operation 〉3 increase the risk of complete previa in mid-pregnancy. Placenta previa is more likely to persist in women with complete previa than those with incomplete previa diagnosed in mid- pregnancy. What is more, women with complete previa in mid-pregnancy delivers earlier.

Isolation and characterisation of mesenchymal stem cells derived from human placenta tissue

AIM: To explore the feasibility of placenta tissue as a reliable and efficient source for generating mesenchymal stem cells (MSC). METHODS: MSC were generated from human placenta tissue by enzymatic digestion and mechanical dissociation. The placenta MSC (PLC-MSC) were characterized for expression of cell surface markers, embryonic stem cell (ECS) gene expression and their differentiation ability into adipocytes and osteocytes. The immunosuppressive properties of PLC-MSC on resting and phytohemagglutinin (PHA) stimulated allogenic T cells were assessed by means of cell proliferation via incorporation of tritium thymidine (3H-TdR). RESULTS: The generated PLC-MSC appeared as spindle-shaped cells, expressed common MSC surface markers and ESC transcriptional factors. They also differen-tiated into adipogenic and osteogenic lineages when induced. However, continuous cultivation up to passage 15 caused changes in morphological appearance and cellular senescence, although the stem cell nature of their protein expression was unchanged. In terms of their immunosuppressive properties, PLC-MSC were unable to stimulate resting T cell proliferation; they inhibited the PHA stimulated T cells in a dose dependent manner through cell to cell contact. In our study, MSC generated from human placenta exhibited similar mesenchymal cell surface markers; MSC-like gene expression pattern and MSC-like differentiation potential were comparable to other sources of MSC. CONCLUSION: We suggest that placenta tissues can serve as an alternative source of MSC for future experimental and clinical studies.

Role of Axonal Guidance Factor Netrin-1 in Human Placental Vascular Growth

This study investigated the role of netrin-1 in placental vascular development. In vitro rat aortic ring assay and in vivo Matrigel plug assay were conducted to exmaine the effect of netrin-1 on angiogenesis. Human placental microvascular endothelial cells （HPMECs） were isolated and cultured and their viability, migration and tubular formation were studied, in order to examine the effects of netrin-1. The results showed that netrin-1 potently stimulated neovascularization in a mouse Matrigel plug in vivo and the sprouting of endothelial cells in rat aortic rings in vitro. In addition, netrin-1 enhanced the viability, migration and tube formation of HPMECs. Our study suggested that netrin-1 could significantly promote the formation of blood vessels of human placenta and may be a potential target for developing new therapeutic strategies for placental vasculature-related diseases.

Evaluation of “J”-shaped Uterine Incision during Caesarean Section in Patients with Placenta Previa:A Retrospective Study

This study evaluated the efficacy and safety of ＂J＂-shaped uterine incision for caesarean section for patients diagnosed with placenta previa. A total of 55 consecutive cases of placenta previa treated in Union Hospital were retrospectively analyzed over a period of two years and 10 months. The subjects were divided into two groups with respect to the uterine incision. Twenty-four pregnant women with placenta previa who were indicated for caesarean section underwent the procedure using a new ＂J＂-shaped uterine incision and 31 pregnant women with placenta previa received caesarean section that used the traditional transverse incision. The two groups were compared in terms of operation time, estimated blood loss, infant expulsion time, exhaust time and postoperative recovery. Meanwhile, comparison was also made in neonatal clinical data between the two groups. Compared with the ＂J＂-shaped incision group, the traditional incision group had a lower Apgar scores （P〈0.05）. However, there existed no statistically significant differences in the overall time of operation and postoperative period of breaking wind （P〉0.05）. It is concluded that, with caesarean section for placenta previa patients, the ＂J＂-shaped uterine incision significantly decreases intraoperative blood loss and facilitates the fetal delivery.

Mesenchymal stem cells derived from human placenta suppress allogeneic umbilical cord blood lymphocyte proliferation

Human placenta-derived mononuclear cells （MNC） were isolated by a Percoll density gradient and cultured in mesenchymal stem cell （MSC） maintenance medium. The homogenous layer of adherent cells exhibited a typical fibroblastlike morphology, a large expansive potential, and cell cycle characteristics including a subset of quiescent cells. In vitro differentiation assays showed the tripotential differentiation capacity of these cells toward adipogenic, osteogenic and chondrogenic lineages. Flow cytometry analyses and immunocytochemistry stain showed that placental MSC was a homogeneous cell population devoid of hematopoietic cells, which uniformly expressed CD29, CD44, CD73, CD105, CD166, laminin, fibronectin and vimentin while being negative for expression of CD31, CD34, CD45 and m-smooth muscle actin. Most importantly, immuno-phenotypic analyses demonstrated that these cells expressed class Ⅰ major histocompatibility complex （MHC-I）, but they did not express MHC-Ⅱ molecules. Additionally these cells could suppress umbilical cord blood （UCB） lymphocytes proliferation induced by cellular or nonspecific mitogenic stimuli. This strongly implies that they may have potential application in allograft transplantation. Since placenta and UCB are homogeneous, the MSC derived from human placenta can be transplanted combined with hematopoietic stem cells （HSC） from UCB to reduce the potential graft-versus-host disease （GVHD） in recipients.

Long-term follow-up of abdominal aortic balloon occlusion for the treatment of pernicious placenta previa with placenta accreta

Objective:To evaluate the efficacy and safety of balloon occlusion of the abdominal aorta for the treatment of pernicious placenta previa with placenta accreta.Methods:The clinical data of 623 patients with pernicious placenta previa combined with placenta accrete,who were admitted to our hospital from January 2013 to January 2019 were retrospectively analyzed.All patients underwent abdominal aortic balloon occlusion combined with cesarean section,and 78 patients underwent sequential bilateral uterine artery embolization.We analyzed the operation time,intraoperative blood loss,blood transfusion volume,intraoperative and postoperative complications,fetal radiation exposure time and dose,and the Apgar score of the newborns.We also performed other evaluations to ascertain the efficacy and safety of abdominal aortic balloon occlusion treatment for dangerous placenta previa with placenta accrete.Results:Of the 623 patients,545 underwent only abdominal aortic balloon occlusion,and 78 underwent uterine artery embolization due to intraoperative or postoperative bleeding.The uterus was successfully preserved in all patients.Except for five cases of right lower extremity arterial thrombosis,the remaining patients did not have postoperative lower extremity arteriovenous thrombosis,renal insufficiency,late postpartum hemorrhage,ectopic embolism,spinal cord or peripheral nerve damage,pelvic infection,or other serious complications.The mean operative time was 65.3(±14.5)min.The mean intraoperative blood loss was620(±570)ml.Ninety-six patients(15.4%,96/623)were treated with blood transfusion,and the average amount of blood transfused was 750(±400)ml.The average number of hospitalization days was 6.8(±3.4)days,the average time of fetal ray exposure was 5.2(±1.6)s,and the average radiation dose was 4.1(±2.7)m Gy.The neonatal Apgar score,was 8.4(±0.6)points at 1 min,and 9.6(±0.4)points at 5 min.In the follow-up to May 31,2019,29 patients were lost to follow-up,96 were lactating,and 498 were menstruating.Except for the cases lost to follow-up,the remaining 596 surviving newborns(including 2 twins)showed no abnormalities at the 42-day postnatal outpatient follow-up examination.Conclusion:Balloon occlusion of the abdominal aorta is a safe and effective method for the treatment of pernicious placenta previa with placenta accreta.