Perturbation of fetal liver hematopoietic stem and progenitor cell development by trisomy 21.

The 40-fold increase in childhood megakaryocyte-erythroid and B-cell leukemia in Down syndrome implicates trisomy 21 (T21) in perturbing fetal hematopoiesis. Here, we show that compared with primary disomic controls, primary T21 fetal liver (FL) hematopoietic stem cells (HSC) and megakaryocyte-erythroid progenitors are markedly increased, whereas granulocyte-macrophage progenitors are reduced. Commensurately, HSC and megakaryocyte-erythroid progenitors show higher clonogenicity, with increased megakaryocyte, megakaryocyte-erythroid, and replatable blast colonies. Biased megakaryocyte-erythroid-primed gene expression was detected as early as the HSC compartment. In lymphopoiesis, T21 FL lymphoid-primed multipotential progenitors and early lymphoid progenitor numbers are maintained, but there was a 10-fold reduction in committed PreproB-lymphoid progenitors and the functional B-cell potential of HSC and early lymphoid progenitor is severely impaired, in tandem with reduced early lymphoid gene expression. The same pattern was seen in all T21 FL samples and no samples had GATA1 mutations. Therefore, T21 itself causes multiple distinct defects in FL myelo- and lymphopoiesis.

A fetus with de novo 2q33.2q35 deletion including MAP2 with brain anomalies, esophageal atresia, and laryngeal stenosis.

Deletions of the long arm of chromosome 2 are rare. Few cases of interstitial deletions of the 2q33q35 region have been reported. Individuals with deletions in this region have growth retardation, psychomotor retardation, micrognathia, microcephaly, and apparently low-set ears. We describe a female fetus with a de novo deletion of 2q33.2 to q35 with delayed gyral formation with widespread neuronal heterotopia of the white matter, small cerebellum, esophageal atresia, laryngeal stenosis, micrognathia, and intrauterine growth retardation. With the use of karyotyping and high-resolution array comparative genomic hybridization the boundaries and gene content of the deletion were identified. Our aim was to determine whether a candidate gene for the brain phenotype was present in the deletion. By this means and based on literature we pinpointed the microtubule associated gene MAP2 as a candidate for the brain anomalies.

Microglia activation in the extremely preterm human brain.

BACKGROUND: The periventricular white matter (PVWM) of the immature preterm brain is selectively vulnerable to a spectrum of injury. Although essential for normal brain development, the presence of resident microglia may exacerbate PVWM injury. METHODS: We used immunohistochemistry to investigate microglia profile in human preterm noninjured control brains and in brains with evidence of germinal matrix hemorrhage/intraventricular hemorrhage (GMH/IVH), with median gestational age (GA) of 24.1 and 25.4 wk, respectively. RESULTS: The number of microglia in the PVWM was higher than the other brain regions in both the control and GMH/IVH groups. Microglial density increased further in the PVWM of GMH/IVH brains, regardless of hemorrhage severity and despite normal macroscopic and imaging appearances to the PVWM. This was due to an increase in activated Iba1/CD68- and not Iba/CD45-immunopositive microglia. However, there were very few CD68/Ki67 colocalized cells, suggesting that the source of this increase may be due to a quick transformation of CD45-immunopositive hematopoietic microglia into CD68-immunopositive microglia. There was also increased apoptosis in the PVWM of all cases of GMH/IVH, with axonal injury and increased tumor necrosis factor-α (TNF-α) expression evident in the most severe cases. CONCLUSION: Isolated GMH/IVH may influence ongoing brain development, with a significant role played by microglial activation.

Accuracy of prenatal diagnosis and prediction of lethality for fetal skeletal dysplasias.

OBJECTIVES: We reviewed all cases with fetal skeletal dysplasia and correlated the accuracy of prenatal diagnoses with the final post-mortem, radiological, or molecular diagnoses. The accuracy of prenatal prediction of lethality was also reviewed. METHODS: All cases of fetal skeletal dysplasia referred between October 2002 and August 2010 were reviewed. Perinatal outcome, the accuracy of prenatal diagnosis, and prediction of lethality were ascertained. Lethality was suspected when significant thoracic narrowing, severe micromelia, multiple fractures, or long bone bowing was present. RESULTS: There were 40 cases of skeletal dysplasia. Thirty-nine (97.5%) were singletons and one (2.5%) was a dichorionic twin pregnancy. Twenty-eight (70%) pregnancies were terminated, five (12.5%) were stillborn, and only seven (17.5%) cases were live born. A final diagnosis was established in 28 (70%) cases. In 29 cases with a presumptive prenatal diagnosis, this was confirmed in 23 (79.3%) cases postnatally. Lethality was predicted with 100% certainty. CONCLUSION: We report higher prenatal/postnatal concordance rates in this series. A precise prenatal diagnosis is frequently difficult and often inaccurate. Prediction of lethality is much easier and often possible with accuracy. Parents need to be aware that the outcome of many skeletal dysplasias is poor.

Bestrophin-3 Expression in a Subpopulation of Astrocytes in the Neonatal Brain After Hypoxic-Ischemic Injury.

Bestrophin-3, a potential candidate for a calcium-activated chloride channel, recently was suggested to have cell-protective functions. We studied the expression and alternative splicing of bestrophin-3 in neonatal mouse brain and after hypoxic-ischemic (HI) injury and in human neonatal brain samples. HI brain injury was induced in 9-day old mice by unilateral permanent common carotid artery occlusion in combination with exposure to 10% oxygen for 50 min. Endoplasmic reticulum stress was induced by thapsigargin treatment in primary culture of mouse brain astrocytes. We also investigated expression of bestrophin-3 protein in a sample of human neonatal brain tissue. Bestrophin-3 protein expression was detected with immunohistochemical methods and western blot; mRNA expression and splicing were analyzed by RT-PCR. HI induced a brain tissue infarct and a pronounced increase in the endoplasmic reticulum-associated marker CHOP. Three days after HI a population of astrocytes co-expressed bestrophin-3 and nestin in a penumbra-like area of the injured hemisphere. However, total levels of Bestrophin-3 protein in mouse cortex were reduced after injury. Mouse astrocytes in primary culture also expressed bestrophin-3 protein, the amount of which was reduced by endoplasmic reticulum stress. Bestrophin-3 protein was detected in astrocytes in the hippocampal region of the human neonatal brain which had patchy white matter gliosis and neuronal loss in the Sommer's sector of the Ammon's horn (CA1). Analysis of bestrophin-3 mRNA in mouse brain with and without injury showed the presence of two truncated spliced variants, but no full-length mRNA. Total amount of bestrophin-3 mRNA increased after HI, but showed only minor injury-related change. However, the splice variants of bestrophin-3 mRNA were differentially regulated after HI depending on the presence of tissue injury. Our results show that bestrophin-3 is expressed in neonatal mouse brain after injury and in the human neonatal brain with pathology. In mouse brain bestrophin-3 protein is upregulated in a specific astrocyte population after injury and is co-expressed with nestin. Splice variants of bestrophin-3 mRNA respond differently to HI, which might indicate their different roles in tissue injury.

Fetal cells in the maternal appendix: a marker of inflammation or fetal tissue repair?

BACKGROUND: Fetal microchimeric cells that have trafficked into the maternal circulation persist in maternal tissues for years after pregnancy, but their biological role is unclear. We investigated whether fetal cells participate in maternal tissue repair during human pregnancy. METHODS: Appendix specimens were acquired from women undergoing appendicectomy during (n = 8) or after (n = 1) pregnancy. Fluorescence in situ hybridization (FISH) determined the presence of male presumed-fetal cells, and immunostaining indicated the fetal cell phenotype. RESULTS: Male cells were identified in appendiceal tissues from all women with known present or past male pregnancies (n = 7) and from a woman with a previous spontaneous abortion of undetermined gender (n = 1), but not in one woman with three daughters. One woman was only 6 weeks pregnant at appendicectomy. Male cells were evenly distributed through appendix tissues, in larger numbers where there was a greater degree of inflammation and when the current pregnancy was male. Combined immunostaining and Y-FISH demonstrated male desmin+ muscle cells and CD3+ lymphocytes, suggesting fetal cells had differentiated. CONCLUSIONS: Male-presumed fetal cells of haematopoietic and mesenchymal origin were identified in the appendix of all pregnant women who had sons. We suggest that fetal cells are present at sites of maternal tissue injury during pregnancy, and may participate in tissue repair.

Pregnancy loss after first trimester viability in women with sickle cell trait: a preliminary report.

BACKGROUND: Traditionally, sickle cell trait has not been associated with a higher risk of fetal death, but we noted several, which led us to assess all such pregnancies. METHODS: In this retrospective study, 131 patients with sickle cell trait were analyzed over a two-year period. The Institutional Review Board approved the collection of deidentified data. RESULTS: Subjects were African-American with an average age of 23.9 years, and average gestational age at delivery of 30.1 weeks. There were 10 (8.13%) intrauterine fetal deaths (IUFDs), and one neonatal death. Ascending amniotic fluid infection was noted in 50% and 92% meconium histocytes. All placentas had sickling in the intervillous space and the decidual vessels. CONCLUSIONS: Sickling in the decidual vessels and poor placental perfusion may play a role in pregnancy loss in excess of what has previously been reported. A cohort control study appears to be in order. NARRATIVE: Pregnant women with sickle cell trait are thought not to have increased maternal or fetal mortality/morbidity. Over a two year period, we studied 131 women with this hemoglobinopathy and found that 10.6% had intrauterine growth retardation (IUGR), 8.4% preterm premature rupture of the membranes, 8.1% intrauterine fetal demise (n = 10) at most occurring at 16 to 24 weeks, and one neonatal death. Amniotic fluid infection was noted in 50%, and meconium histocytes indicating intrauterine hypoxia were noted, as was unsuspected sickling in the placental vasculature. Based on this case series, sickle cell trait may not be as benign for the fetus as was previously thought.

Pregnancy loss after first-trimester viability in women with sickle cell trait: time for a reappraisal?

OBJECTIVE: The purpose of this study was to evaluate the obstetric outcomes and pathologic findings in women with sickle cell trait. STUDY DESIGN: In this retrospective case control study, pregnant women with sickle cell trait were studied over a 4-year period (2001-2005). The women who were delivered at > 16 weeks of gestation were compared with a cohort group of subjects with normal hemoglobin levels, and the placentas were sent for pathologic evaluation. RESULTS: A total of 180 pregnancies were studied with a like number of control patients. Subjects who had sickle cell trait demonstrated shorter average duration of pregnancy (233 +/- 45 days vs 255 +/- 34 days; P < .001) and lower birth weight (2114 +/- 1093 g vs 2672 +/- 942 g; P < .001). The rate of fetal death was significantly higher among study group patients (3.5% vs 9.7%; P = .015) when compared with the control group. Additionally, in study women, acute ascending amniotic infection and meconium histiocytosis were noted much more frequently. Sickling in the intervillous space and decidual vessels that were not associated with artifactual change was also found among patients sickle cell trait. CONCLUSION: Patients with sickle cell trait appear to be at increased risk for fetal loss compared with women with normal hemoglobin levels, and placental abnormalities may play a causal role.

Cellular mechanisms of toll-like receptor-3 activation in the thalamus are associated with white matter injury in the developing brain.

Toll-like receptor-3 (TLR3) has been identified in a variety of intracellular structures (e.g. endosomes and endoplasmic reticulum); it detects viral molecular patterns and damage-associated molecular patterns. We hypothesized that, after white matter injury (WMI) has occurred, localization and activation of TLR3 are altered in gray matter structures in response to damage-associated molecular patterns and activated glia. Therefore, we investigated the subcellular localization of TLR3 and its downstream signaling pathway in postmortem brain sections from preterm infants with and without WMI (7 patients each). We assessed astroglia (glial fibrillary acidic protein-positive), microglia (ionized calcium-binding adaptor molecule-1-positive), and neuronal populations in 3 regions of the thalamus and in the posterior limb of the internal capsule and analyzed TLR3 messenger RNA and protein expression in the ventral lateral posterior thalamic region, an area associated with impaired motor function. We also assessed TLR3 colocalization with late endosomes (lysosome-associated membrane protein-1) and phagosomal compartments in this region. Glial fibrillary acidic protein, ionized calcium-binding adaptor molecule-1, and TLR3 immunoreactivity and messenger RNA expression were increased in cases with WMI compared with controls. In ventral lateral posterior neurons, TLR3 was colocalized with the endoplasmic reticulum and the autophagosome, suggesting that autophagy may be a stress response associated with WMI. Thus, alterations in TLR3 expression in WMI may be an underlying molecular mechanism associated with impaired development in preterm infants.

Recurrent neoaortic insufficiency after the switch back operation with previous repair of transposition with ventricular septal defect and aortic arch hypoplasia.

Neoaortic insufficiency is not uncommon after the arterial switch operation (ASO) for d-Transposition, yet surgery is rarely required. In a patient with worsening neoaortic regurgitation post-arterial switch and ventricular septal defect (VSD) closure, we performed a successful "switch back" operation with documented aortic valve competence on discharge echocardiography. However, recurrent severe aortic insufficiency required valve replacement, and histopathology of the excised valve indicated abnormal leaflet/vascular wall structure. We question whether the switch back operation is a viable option for neoaortic insufficiency after an ASO in patients with previous d-Transposition and VSD, when the native pulmonary valve may have structural deficiencies.

Hepatic heterotopia in congenital diaphragmatic anomaly.

An antenatally diagnosed case of a left congenital diaphragmatic hernia is reported. The diaphragmatic eventration hernia sac consisted of a sheet of ectopic liver tissue in continuity with a hypoplastic left lobe which formed the medial anterior and posterior walls of the hernia is presented. The operative management of this combination of defects has not previously been described in English literature. Embryological considerations, limitations of accurate preoperative diagnosis, technical challenge in the operative repair of the defect and need for drainage is discussed.

Antenatal closure of the ductus arteriosus and hydrops fetalis.

Antenatal closure of the ductus arteriosus has been speculated, but rarely reported, as a cause of hydrops fetalis. The purpose of this prospective autopsy study was to find the incidence of antenatal closure of the ductus arteriosus and hydrops fetalis in a high-risk obstetric population and to find associated factors that might give clues to the cause of antenatal closure of the ductus arteriosus. Antenatal closure of the ductus arteriosus had to be stringently sought by in situ examination. Fifteen stillborns with antenatal closure of the ductus arteriosus were found in 684 perinatal autopsies (2.2%), including 511 stillborns (2.9%). All 15 stillborns with antenatal closure of the ductus arteriosus also had hydrops fetalis and accounted for 35% of the 43 stillborns with hydrops fetalis. Antenatal closure of the ductus arteriosus in these 15 stillborns was not associated with maternal aspirin use but was associated with a myriad of factors, including intrauterine infection (60%), umbilical cord abnormalities (67%), and retroplacental hemorrhage (87%), that can cause hypoxic-ischemic stress.

Absence of neurotoxicity with medicinal grade terbutaline in the rat model.

To evaluate neurological effects of terbutaline, rats were injected with saline, terbutaline (Sigma or American Pharmaceutical Partners (APP™)) at 0.5 mg/kg-d or 10 mg/kg-d between postnatal days (PND) 2-5 or 11-14. Brains collected 24 h after last injection were used to determine corpus-callosum thickness, Purkinje cell and neuronal number in the cerebellum. Ambulation, distance traveled, resting time and time on rotarod were analyzed. Terbutaline (both doses/grades at PND 11-14) decreased corpus-callosum thickness. Ambulation time was significantly decreased in the 10 mg/kg-d (Sigma) and 0.5 mg/kg-d of terbutaline (APP™) (PND 2-5) juvenile-rats and 10 mg/kg-d-Sigma adult-rats, 0.5 mg/kg-d APP™ (PND 11-14) adult-rats. Resting time was increased in both doses of APP™ (PND 2-5) in juvenile-rats, 10 mg/kg-d Sigma adult-rats. 10 mg/kg-d-Sigma (PND 2-5) decreased distance traveled in adult-rats. 0.5 mg/kg-d-Sigma (PND 2-5 and PND 11-14) decreased the time spent on rotarod (30 RPM) in adult-rats. Sigma terbutaline Sigma had 2× as much free base compared to APP™. In conclusion, APP™ terbutaline did not have a deleterious effect on the developing rat brain.

Microchimeric fetal cells cluster at sites of tissue injury in lung decades after pregnancy.

Fetal cells trafficking into maternal blood during pregnancy engraft tissues and persist for decades in marrow and bone. While persistent fetal cells were initially implicated in autoimmune disease, animal studies suggest that microchimeric fetal cells play a broader role in response to tissue injury. This study investigated whether fetal cells participate in tissue repair after human pregnancy. Specimens were obtained from women undergoing surgery for suspected lung cancer. Y-fluorescence in-situ hybridization was performed on paraffin-embedded sections, with the investigator blinded to medical histories. Male cells were identified in lung/thymus tissue from all women with known male pregnancies, but not in those without sons. The frequency of male microchimeric cells was seven-fold greater in lung/thymus tissues than marrow and was two-fold greater than normal bone from the same women. Nested-polymerase chain reaction for sex determining region Y confirmed male DNA in tissues. Male cells in lung were clustered in tumour rather than surrounding healthy tissues. In conclusion, male presumed-fetal cells were identified in pathological post-reproductive tissues, where they were more likely to be located in diseased tissues at several-fold higher frequency than normal tissues. It is suggested that fetal cells are present at sites of tissue injury and may be stem cells, either recruited from marrow or having proliferated locally.

Benign müllerian papilloma of childhood.

Benign müllerian papilloma of the female reproductive tract is a rare childhood tumor that can easily be mistaken by those unfamiliar with the entity for botryoid rhabdomyosarcoma. Ultrastructural findings have been mentioned only in two individual case reports, and these both were issued many years ago. The aim of this update is to familiarize the reader with the clinical, light, and electron microscopic features associated with this distinctive entity, and thereby hopefully preclude the risk of making a serious diagnostic error. Two cases are illustrated, one very typical in its presentation and the other less so.

Colonic chicken-skin mucosa in children with polyps is not a preneoplastic lesion.

Colonic polyps are common both in adults and children; however, the malignant potential varies according to the type of polyp. Most childhood polyps are solitary juvenile polyps, which have negligible malignant potential. Chicken-skin mucosa (CSM) is an endoscopic finding initially described associated with adenomatous polyps and adenocarcinoma, suggesting a preneoplastic lesion. Subsequently, CSM was described in association with juvenile polyps, suggesting that this mucosal finding is not a precursor to dysplasia. To determine whether CSM represents a preneoplastic lesion, we studied endoscopic colonic mucosal biopsies for markers of cell replication (Ki-67) and malignant transformation (p53) in mucosal biopsies of CSM, normal colonic tissue, tubular adenomas, and adenocarcinomas. Samples were subjected to immunostaining for the presence of Ki-67 and p53. The degree of Ki-67-positive staining cells was similar for CSM and normal colonic tissue, whereas there was significantly increased staining for both tubular adenomas and adenocarcinomas. There was no evidence of p53 staining in CSM and normal colonic mucosa, whereas there was varying degrees of staining in tubular adenomas and adenocarcinomas. The association of CSM with benign juvenile polyps and the absence of histologic markers for increased replication and malignant transformation support the notion that this endoscopic finding is not preneoplastic. Rather, CSM arises in proximity to polyps of all histologic types because of local mucosal damage.

Recurrent neuroblastoma with gastric invasion.

The authors present an unusual manifestation of neuroblastoma in a young child: upper gastrointestinal bleeding due to erosion of the tumor into the stomach. Included are reviews of gastrointestinal manifestations of neuroblastoma and gastric tumors in children.