Socioeconomic Deprivation and Utilization of Anesthetic Care During Pregnancy and Delivery: A Secondary Analysis of a French Prospective, Multicenter, Cohort Study.

BACKGROUND: Socioeconomic deprivation is associated with reduced use of antenatal resources and poor maternal outcomes with pregnancy. Research examining the association between socioeconomic deprivation and use of obstetric anesthesia care in a country providing universal health coverage is scarce. We hypothesized that in a country providing universal health coverage, France, socioeconomic deprivation is not associated with reduced use of anesthetic care during pregnancy and delivery. This study aimed to examine the association between socioeconomic deprivation and (1) completion of a mandatory preanesthetic evaluation during pregnancy and (2) use of neuraxial analgesia during labor. METHODS: Data were from a cohort of 10,419 women who delivered between 2010 and 2011 in 4 public teaching hospitals in Paris. We used a deprivation index that included 4 criteria: social isolation, poor housing condition, no work-related household income, and state-funded health care insurance. Socioeconomic deprivation was defined as a deprivation index greater than 1. Preanesthetic evaluation was considered completed if performed more than 48 hours before delivery. The association between socioeconomic deprivation and completion of the preanesthetic evaluation and use of neuraxial labor analgesia was assessed by multivariable logistic regression adjusting for education level, country of birth, and maternal and pregnancy characteristics. RESULTS: Preanesthetic evaluation was completed for 8142 of the 8624 women (94.4%) analyzed and neuraxial labor analgesia was used by 6258 of the 6834 women analyzed (91.6%). After adjustment, socioeconomic deprivation was associated with reduced probability of completed preanesthetic evaluation (adjusted odds ratio 0.88 [95% confidence interval, 0.79-0.98]; P = .027) but not use of neuraxial labor analgesia (adjusted odds ratio 0.97 [95% confidence interval, 0.87-1.07]; P = .540). CONCLUSIONS: In a country providing universal health care coverage, women who were socioeconomically deprived showed reduced completion of preanesthetic evaluation during pregnancy but not reduced use of neuraxial labor analgesia. Interventions should be targeted to socioeconomically deprived women to increase the completion of the preanesthetic evaluation.

Fetal urine biochemistry in antenatal Bartter syndrome: a case report.

Bartter syndrome is a severe inherited tubulopathy responsible for renal salt wasting, and hence electrolyte disorders and dehydration. Prenatally, it is characterized by severe polyhydramnios caused by fetal polyuria. We studied for the first time fetal urine in a Bartter syndrome case and demonstrated that the tubulopathy is already present at 24 weeks of gestation.

Fertility and pregnancy outcomes following conservative treatment for placenta accreta.

BACKGROUND: The aim of this study was to estimate the fertility and pregnancy outcomes after successful conservative treatment for placenta accreta. METHODS: This retrospective national multicenter study included women with a history of conservative management for placenta accreta in French university hospitals from 1993 through 2007. Success of conservative treatment was defined by uterine preservation. Data were retrieved from medical files and telephone interviews. RESULTS: Follow-up data were available for 96 (73.3%) of the 131 women included in the study. There were eight women who had severe intrauterine synechiae and were amenorrheic. Of the 27 women who wanted more children, 3 women were attempting to become pregnant (mean duration: 11.7 months, range: 7-14 months), and 24 (88.9% [95% confidence interval (CI), 70.8-97.6%]) women had had 34 pregnancies (21 third-trimester deliveries, 1 ectopic pregnancy, 2 elective abortions and 10 miscarriages) with a mean time to conception of 17.3 months (range, 2-48 months). All 21 deliveries had resulted in healthy babies born after 34 weeks of gestation. Placenta accreta recurred in 6 of 21 cases [28.6% (95% CI, 11.3-52.2%)] and was associated with placenta previa in 4 cases. Post-partum hemorrhage occurred in four [19.0% (95% CI, 5.4-41.9%)] cases, related to placenta accreta in three and to uterine atony in one. CONCLUSIONS: Successful conservative treatment for placenta accreta does not appear to compromise the patients' subsequent fertility or obstetrical outcome. Nevertheless, patients should be advised of the high risk that placenta accreta may recur during future pregnancies.

Human foetal hepatocytes: isolation, characterization, and transplantation.

Hepatocyte transplantation has become an alternative to orthotopic liver transplantation for the treatment of liver metabolic diseases. However, there is an increasing lack of donor organs and isolated mature hepatocytes are difficult to manipulate and cannot be expanded in vitro. It is therefore necessary to find alternative sources of hepatocytes, and different approaches to evaluate the therapeutic potential of stem cells of different origins are being developed. Hepatic progenitors (hepatoblasts) and/or foetal hepatocytes isolated from foetal livers may be one potential source to generate fully differentiated hepatocytes. We have reported that human foetal liver cells can be isolated and cultured. These cells also engraft and differentiate into mature hepatocytes in situ after transplantation into immunodeficient mice. Foetal cell populations could also be used as targets for gene therapy since efficient gene transfer is achieved with retroviral vectors. Use of such experimental approaches will help design strategies for clinical applications of liver cell therapy with hepatic progenitors.

Termination of pregnancy following prenatal diagnosis in France: how severe are the foetal anomalies?

OBJECTIVE: To determine how severe were the conditions leading to termination of pregnancy for foetal anomaly (TOPFA) in France. METHODS: Detailed indications for TOPFA were extracted from medical charts. RESULTS: Of 2465 completed records, indications were: chromosomal anomalies n = 963 (39.1%), malformations of a single organ without chromosomal or genetic aetiologies n = 898 (36.4%), multiple malformations without chromosomal or genetic aetiologies n = 238 (9.7%), obstetrical complications n = 161 (6.5%), non-chromosomal genetic diseases n = 158 (6.4%), foetal infections n = 21 (0.9%), unexplained severe oligohydramnios n = 20 (0.8%), foetal exposure to teratogenic agents n = 6. Overall, 33.3% of anomalies were lethal (e.g. anencephaly), 25.2% were expected to result in isolated mental retardation (e.g. Down) and 35.1% in substantial handicap (e.g. myelomeningocele). In 6.4% of cases, the anomaly was either of late onset (e.g. Huntington's disease) or with uncertain prognosis (e.g. agenesis of corpus callosum) or severity was debatable (e.g. single limb agenesis, sickle cell disease). CONCLUSIONS: Although there is no indisputable definition of which anomalies are 'severe', 93.6% of the decisions to terminate the pregnancy were made by women and professionals in reaction to anomalies which clearly were lethal or would lead to substantial physical and/or mental disabilities.

Maternal outcome after conservative treatment of placenta accreta.

OBJECTIVE: To estimate maternal outcome after conservative management of placenta accreta. METHODS: This retrospective multicenter study sought to include all women treated conservatively for placenta accreta in tertiary university hospital centers in France from 1993 to 2007. Conservative management was defined by the obstetrician's decision to leave the placenta in situ, partially or totally, with no attempt to remove it forcibly. The primary outcome was success of conservative treatment, defined by uterine preservation. The secondary outcome was a composite measure of severe maternal morbidity including sepsis, septic shock, peritonitis, uterine necrosis, fistula, injury to adjacent organs, acute pulmonary edema, acute renal failure, deep vein thrombophlebitis or pulmonary embolism, or death. RESULTS: Of the 40 university hospitals that agreed to participate in this study, 25 institutions had used conservative treatment at least once (range 1-46) and had treated a total of 167 women. Conservative treatment was successful for 131 of the women (78.4%, 95% confidence interval [CI] 71.4-84.4%); of the remaining 36 women, 18 had primary hysterectomy and 18 had delayed hysterectomy (10.8% each, 95% CI 6.5-16.5%). Severe maternal morbidity occurred in 10 cases (6.0%, 95% CI 2.9-10.7%). One woman died of myelosuppression and nephrotoxicity related to intraumbilical methotrexate administration. Spontaneous placental resorption occurred in 87 of 116 cases (75.0%, 95% CI 66.1-82.6%), with a median delay from delivery of 13.5 weeks (range 4-60 weeks). CONCLUSION: Conservative treatment for placenta accreta can help women avoid hysterectomy and involves a low rate of severe maternal morbidity in centers with adequate equipment and resources.

The role of HGF on invasive properties and repopulation potential of human fetal hepatic progenitor cells.

UNLABELLED: The success of hepatocyte transplantation has been limited by the low efficiency of transplanted cell integration into liver parenchyma. Human fetal hepatic progenitor cells (hepatoblasts) engraft more effectively than adult hepatocytes in mouse livers. However, the signals required for their integration are not yet fully understood. We investigated the role of HGF on the migration and invasive ability of human hepatic progenitors in vitro and in vivo. Hepatoblasts were isolated from the livers of human fetuses between 10 and 12 weeks of gestation. Their invasive ability was assessed in the presence or absence of HGF. These cells were also transplanted into immunodeficient mice and analyzed by immunohistochemistry. In contrast to TNF-alpha, HGF increased the motogenesis and invasiveness of hepatoblasts, but not of human adult hepatocytes, via phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. The invasive ability of human hepatoblasts correlated with the expression and secretion of matrix metalloproteinases (MMPs). Hepatoblasts stimulated with HGF prior transplantation into newborn mice migrated from the portal area into the hepatic parenchyma. CONCLUSIONS: In contrast to adult hepatocytes, hepatoblasts display invasive ability that can be modulated by HGF in vitro and in vivo.

[Multifetal pregnancy reduction: indications, technical aspects and psychological impact]. / Réduction embryonnaire: indications, techniques, impact psychologique.

High-order multiple pregnancies (triplets and above) are associated with high pediatric mortality and morbidity, mainly due to their premature delivery. Maternal morbidity is also substantially higher than for singleton gestations. The main goal of multifetal pregnancy reduction (MFPR) is to decrease the rate of severe prematurity and its consequences, including neurodevelopmental handicaps. It may also reduce the risk of maternal complications. Transabdominal needle-guided procedures, performed at 10-12 weeks, are the most common technique for MFPR. Transvaginal needle aspiration can be used successfully earlier in gestation (7-8 weeks). Transcervical aspiration is no longer used. There is generally no medical indication for MFPR in twins. MFPR does not reduce the risk of loss of the entire pregnancy before 24 weeks and may increase the risk of a second-trimester miscarriage by 1-2%. MFPR substantially decreases premature delivery rates, cutting the risk of delivery at 29-32 menstrual weeks in triplet pregnancies in half for reductions to twins and by five for reduction to singletons. The positive effect of MFPR on perinatal outcome is incontrovertible for quadruplets and higher-order pregnancies. Advances in perinatal medicine have substantially reduced mortality in premature triplet deliveries, however, and this should be taken into account when considering the potential benefit of MFPR. MFPR is a distressing experience for parents, but seems not to have long-term adverse effects on women's psychological well-being. Maternal distress related to MFPR tends to fade with time. The negative psychological impact of MFPR should be weighed against that related to raising the children from high-order pregnancies. Prevention of high-order multifetal pregnancies is essential and requires careful monitoring of infertility therapies.

Hepatocyte transplantation: studies in preclinical models.

Transplantation of allogeneic or genetically modified autologous hepatocytes may be an alternative to whole-liver transplantation for the treatment of hereditary metabolic liver diseases. Human hepatocytes have already been transplanted in patients, demonstrating the safety and feasibility of both approaches. Although a few cases of allogeneic transplantation have resulted in long-term engraftment and function, only a partial and transient correction of the disease was achieved. This may partly result from a lack of proliferation of transplanted cells. In rodents, transplanted hepatocytes do not proliferate in adult quiescent livers and repopulate recipient livers only when they display a proliferative advantage over resident hepatocytes. Most of these models are not transposable to humans, however. Our aim is to develop preclinical approaches to hepatocyte transplantation in nonhuman primates. We have defined a strategy that increases the engraftment efficiency of transplanted hepatocytes by inducing their proliferation together with that of resident hepatocytes. We have also immortalized simian fetal hepatic progenitor cells and shown that these cells do not proliferate in situ after transplantation into the livers of immunodeficient mice. By contrast early human hepatoblasts repopulate mouse livers more efficiently. However, if we consider the number of cells to be transplanted (one to several billion), the means of expanding and differentiating stem or progenitor cells other than hepatocytes will have to be determined prior to envisaging treating patients.

Leptin and Ob-Rb receptor isoform in the human digestive tract during fetal development.

CONTEXT: Leptin, partially produced by the stomach, is a hormone involved in energy balance and regulation of food intake. It also regulates some digestive functions through its functional receptor Ob-Rb expressed by gastrointestinal epithelial cells. OBJECTIVE: The objective of the study was to investigate the temporal and spatial appearance of Ob-Rb in the human digestive tract and leptin in the stomach. DESIGN: The esophagus, stomach, and intestine samples of 7- to 24-wk-old human fetuses and adult mucosae were studied by RT-PCR, immunohistochemistry, and Western blot. Leptin was measured by RIA in amniotic fluids at 16-33 wk gestation. RESULTS: All mucosae expressed Ob-Rb (mRNA and/or protein) between 7 and 9 wk gestation. Leptin protein appeared by 8 wk in the gastric mucosa, whereas leptin mRNA was detected around 11 wk. Leptin levels in amniotic fluids were significantly higher during the second than during the third trimester. Overall, Ob-Rb immunoreactivity was higher in young fetuses, during the period corresponding to the formation of gastric buds and primitive intestinal crypts and the beginning of differentiation of epithelial cell types, than in the oldest. Leptin added to culture medium of gastrointestinal explants from 10- to 12-wk-old fetuses appeared to affect DNA synthesis as compared with controls, indicating that leptin receptor functionality was developing. CONCLUSIONS: The strong expression of leptin, in amniotic fluid when fetuses begin swallowing then in the gastric mucosa, and the early presence of Ob-Rb in mucosae suggest a possible role for leptin, exerted endoluminally and in a paracrine pathway, in the developmental process (growth and/or maturation) of the human digestive tract.

Paradoxic activation of the renin-angiotensin system in twin-twin transfusion syndrome: an explanation for cardiovascular disturbances in the recipient.

Despite advances in treatment, twin-to-twin transfusion syndrome (TTTS) still carries a high risk for perinatal mortality and morbidity. Simple blood transfer from the donor to the recipient twin cannot explain all of the features of this disease, in particular the recipient's hypertensive cardiomyopathy. We report a case in which TTTS resulted in preterm delivery with early neonatal death of both twins, allowing assessment of the renin angiotensin system (RAS) status of each fetus, both by cord blood renin and aldosterone assay and by renal immunohistochemistry. The donor had severe oliguria/oligohydramnios, whereas the recipient, in addition to severe polyuria/polyhydramnios, had cardiomyopathy, atrioventricular regurgitation, and ascites. Although immunohistochemistry demonstrated that renal secretion of renin was up-regulated in the donor and down-regulated in the recipient, cord blood levels of renin and aldosterone were similar, with high renin levels in both twins. This observation supports the hypothesis that despite renal RAS down-regulation, the recipient is exposed to RAS effectors elaborated in the donor and transferred via placental shunts. This may contribute to cardiomyopathy and hypertension in the recipient, which cannot be accounted for by hypervolemia alone. We thus hypothesized that in TTTS, the recipient's hypertensive cardiomyopathy could be due to a mechanism similar to the classical model of hypertension referred to as "2 kidneys-1 clip." Thus the hypovolemic donor twin, comparable to the clipped kidney, produces vasoactive hormones that compromise the recipient, comparable to the normal kidney, causing hypertension and cardiomyopathy.

Fetal home monitoring for the prenatal management of gastroschisis.

BACKGROUND: Fetal distress is a frequent complication of gastroschisis, and could be screened for by home monitoring, as many pregnant women expecting an affected child live far away from a specialized perinatal center. This study was undertaken to audit a policy of fetal home monitoring (FHM) to achieve early detection of fetal heart rate (FHR) abnormalities in gastroschisis. METHODS: Daily FHM was started at a median age of 30 weeks in 31 pregnant women referred following prenatal diagnosis of isolated gastroschisis. Monitoring was considered abnormal in cases with decelerations, tachycardia, bradycardia, decreased baseline variability or absence of accelerations. When an ominous FHR was detected and confirmed by in-hospital monitoring, an emergency cesarean section (C-section) was indicated. Otherwise, an elective C-section was planned. RESULTS: In 20 cases FHM remained normal. There were 16 elective C-sections, two emergency C-sections for FHR abnormalities detected by in-hospital monitoring, and two spontaneous premature vaginal deliveries. In 11 cases, an abnormal FHM was detected. There was one intrauterine death with acute ischemic necrosis of the large bowel. The other abnormalities consisted of decreased baseline variability with tachycardia (n = 7) or without tachycardia (n = 3) and were confirmed by in-hospital follow-up in nine cases, leading to emergency C-section. CONCLUSION: The high rate of abnormal FHR patterns picked up by FHM in gastroschisis led to a rate of emergency C-sections of 9/31. However, this strategy failed to prevent one intrauterine death due to acute bowel necrosis.

Evaluation of fetal pulmonary vasculature by power Doppler imaging in congenital diaphragmatic hernia.

OBJECTIVE: To evaluate the feasibility of prenatal power Doppler imaging of pulmonary arteries in congenital diaphragmatic hernia and to study its potential to predict outcome. METHODS: A prospective observational study was conducted. Forty-two cases of congenital diaphragmatic hernia (32 left and 10 right) without associated anomalies were analyzed. Qualitative evaluation of pulmonary vasculature was based on power Doppler imaging performed at 26 to 38 weeks. The pulmonary arteries were studied in the lung contralateral to the hernia. Pulmonary Doppler angiography was considered satisfactory when 3 levels of bifurcation defining 3 distinct segments of the pulmonary arteries were imaged and was otherwise considered poor. We also recorded the gestational age at diagnosis, side of the hernia, abdominal circumference below the third percentile, amniotic fluid volume, lung/thoracic area ratio, left/right ventricle ratio, and, in left-sided hernias, stomach position, and we carried out a multivariate analysis to determine the contribution of each factor to predict neonatal mortality. RESULTS: More than 3 divisions of the fetal pulmonary arteries were imaged in 20 cases; 1 or 2 divisions or none were imaged in 22. Neonatal mortality was significantly greater when fewer than 3 divisions of the pulmonary arteries were imaged (18 [82%] of 22) than when 3 divisions could be identified on power Doppler imaging (5 [25%] of 20; P = .0005). However, the lung/thoracic area ratio was the only factor that remained significantly associated with mortality in the multivariate analysis. CONCLUSIONS: An altered pulmonary power Doppler image is associated with neonatal mortality, but estimation of the lung area remains the best predictor of neonatal outcome.

Abnormal production of the TNF-homologue APRIL increases the proliferation of human malignant glioblastoma cell lines via a specific receptor.

A proliferation-inducing ligand (APRIL) of the tumour necrosis factor (TNF) family is produced in small amounts in many tissues and more abundantly in tumours. APRIL has been reported to promote cell growth in vivo and in vitro. It was recently shown that the production of APRIL in some glioblastoma cell lines does not lead to an increase in cell growth. In this study, we investigated the production of APRIL and its ability to increase the proliferation of eight human glioblastoma cell lines. We found that APRIL was produced in the eight human glioblastoma cell lines tested but not in the normal embryonic astrocyte counterparts of glioblastomas. Flow cytometry demonstrated the presence of a specific APRIL-binding receptor on the cell surface in all the glioblastoma cell lines tested. This receptor was also present on normal embryonic and adult astrocytes and embryonic neural progenitor cells. Moreover, the addition of recombinant human APRIL resulted in an increase in proliferation rate of normal adult astrocytes and in four of eight cell lines tested. Addition of the soluble recombinant TNF-receptor-homologue B-cell maturation (BCMA) chimeric protein, which binds APRIL, confirmed the involvement of APRIL in the growth of malignant glioblastoma cell lines.

In utero allotransplantation of fetal hepatocytes in primates.

OBJECTIVE: Because intrauterine transplantation of fetal hepatocytes could become an effective approach for treating severe genetic disorders of the liver, the objective of this study was to demonstrate the feasibility of in utero allotransplantation of fetal hepatocytes in a nonhuman primate model using direct intraparenchymal administration of donor cells. METHODS: Fetal primary hepatocytes were isolated from 3 fetal primates (MACACA MULATTA) at 89-120 days of gestation, and cryopreserved. When a recipient was available, the cells were thawed and transduced by a beta-galactosidase-expressing retrovirus (3 cases) or labelled with a fluorescent dye (4 cases). Hepatocytes were infused directly into the fetal liver under surgical visual control. Engraftment was assessed by surgical liver biopsies taken 8-60 days following transplantation. RESULTS: Six recipients survived until liver biopsy, and 1 died during the surgical procedure. There was no evidence of engraftment in the 3 fetuses that received genetically marked hepatocytes. All 3 monkeys who received 20-25 x 10(6) hepatocytes from an 89-day-old donor labelled with fluorescent dye had positive liver biopsies 8-11 days following intrauterine transplantation. CONCLUSIONS: In utero allotransplantation of fetal hepatocytes is feasible in the nonhuman primate, and direct intraparenchymal administration enables short-term detection of persisting donor hepatocytes.

Repopulation of athymic mouse liver by cryopreserved early human fetal hepatoblasts.

Transplantation of hepatocytes is a promising alternative to liver transplantation for the treatment of severe liver diseases. However, this approach is hampered by the shortage of donor organs and intrinsic limitations of adult hepatocytes. To investigate whether most of the hurdles faced with adult hepatocytes could be surmounted by the use of human fetal hepatoblasts, we have developed a method to isolate, transduce, and cryopreserve hepatoblasts from human livers at an early stage of development (11-13 weeks of gestation). Cells were characterized in vitro for expression of specific markers, and in vivo for their proliferation and differentiation potential after transplantation into athymic mice. Most of the cells (80-90%) harbored a bipotent phenotype, expressing cytokeratins 8/18, albumin, and CK19. They proliferated spontaneously in culture and were efficiently transduced by a beta-galactosidase-expressing retrovirus (90%). After transplantation, cryopreserved cells engrafted into the liver of athymic mice and proliferated, resulting in up to 10% repopulation. Engrafted cells expressed markers of differentiated adult hepatocytes including albumin, alpha1-antitrypsin, cytochrome P450 3A4, and alpha-glutathione-S-transferase. When retrovirally transduced before transplantation they expressed the transgene in vivo. In summary, early human fetal hepatoblasts engraft, proliferate, and mature in athymic mouse liver, without conditioning the donor.

Feticide during second- and third-trimester termination of pregnancy: opinions of health care professionals.

OBJECTIVE: To study the opinions of professionals on feticide being performed as the first step of late termination of pregnancy (TOP). SETTING: Tertiary care obstetrical unit with policy of routine feticide in late TOP. METHOD: Questionnaire survey. RESULTS: 101/109 professionals responded (23 midwives, 22 doctors, 24 nurses, 21 auxiliaries, 9 others). 90 had heard of feticide, 83 knew about how and 38 about when the procedure was done. When asked about what the goals of feticide were, 94 respondents quoted, 'preventing parents from facing neonatal agony', 73 'avoiding fetal pain', 85 'preventing labor ward staff from facing neonatal agony', and 60 'complying with legal rules'. 54 respondents thought feticide was beneficial to their patients or improved their own professional practice, and 71 declared the procedure was emotionally positive, yet stressful. 48 respondents declared lacking information on feticide. Respondents who had attended to feticide at least once (n = 59) knew more on feticide, and were more positive on the impact feticide had on their practice than those who had never attended a feticide (n = 42). CONCLUSIONS: In a highly specialized center, professionals had positive opinions on feticide, expecting it would avoid fetal or neonatal agony and pain.

Amniotic fluid beta-endorphin: a prognostic marker for gastroschisis?

PURPOSE: The aim of this work was to study amniotic fluid beta-endorphin as a potential predictor for postnatal morbidity in gastroschisis. METHODS: Beta-endorphin was assayed in 43 amniotic fluid samples from 13 pregnant women with fetal gastroschisis undergoing diagnostic amniocentesis or therapeutic amnioinfusion and compared with 33 controls. Within the gastroschisis group, the authors investigated the relationship between postnatal morbidity and the peak value of amniotic fluid beta-endorphin (AFBE). RESULTS: Ten AFBE values in 6 cases of gastroschisis were above the upper limit of the 95% confidence interval derived from controls. Postnatal morbidity was significantly higher when peak AFBE exceeded 10 microg/L (n = 4 pregnancies) compared with below 5 microg/L (n = 9 pregnancies), as shown by mean duration of mechanical ventilation (15.2 v 3 days; P =.01), of parenteral feeding (77 v. 18.7 days; P =.04), and of hospitalization (84 v 32.2 days; P =.04). There was no statistically significant association between postnatal morbidity markers and prenatal dilation of fetal bowel. CONCLUSIONS: The most severe cases of gastroschisis are associated with high levels of AFBE. The authors speculate that this fetal hormonal response could result from stress or pain caused by prenatal bowel damage.

Immortalization of a primate bipotent epithelial liver stem cell.

Liver regeneration after partial hepatectomy results primarily from the simple division of mature hepatocytes. However, during embryonic and fetal development or in circumstances under which postnatal hepatocytes are injured, organ regeneration is believed to occur from a compartment of epithelial liver stem or progenitor cells with biliary and hepatocytic bipotentiality. The ability to identify, isolate, and transplant epithelial liver stem cells from fetal liver would greatly facilitate the treatment of hepatic diseases currently requiring orthotopic liver transplantation. Here we report the identification and immortalization by retrovirus-mediated transfer of the simian virus 40 large T antigen gene of primate fetal epithelial liver cells with a dual hepatocytic biliary phenotype. These cells grow indefinitely in vitro and express the liver epithelial cell markers cytokeratins 8/18, the hepatocyte-specific markers albumin and alpha-fetoprotein, and the biliary-specific markers cytokeratins 7 and 19. Bipotentiality of gene expression was confirmed by clonal analysis initiated from single cells. Endogenous telomerase also is expressed constitutively. After orthotopic transplantation via the portal vein, approximately 50% of the injected cells integrated into the liver parenchyma of athymic mice without tumorigenicity. Three weeks after transplantation, cells having seeded in the liver parenchyma expressed both albumin and alpha-fetoprotein but had lost expression of cytokeratin 19. These results provide strong evidence for the existence of a bipotent epithelial liver stem cell in nonhuman primates. This unlimited source of donor cells also should enable the establishment of a model of allogenic liver cell transplantation in a large animal closely related to humans and shed light on important questions related to liver organogenesis and differentiation.