Management of pregnancies with RhD alloimmunisation.
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Anemia, Neonatal↗
Biomedical subjects
Sailesh Kumar
Publications and source records attributed to Sailesh Kumar.
Human fetal mesenchymal stem cells as vehicles for gene delivery.
First-trimester fetal blood contains a readily expandable population of stem cells, human fetal mesenchymal stem cells (hfMSCs), which might be exploited for autologous intrauterine gene therapy. We investigated the self-renewal and differentiation of hfMSCs after transduction with onco-retroviral and lentiviral vectors. After transduction with either a MoMuLV retrovirus or an HIV-1-based lentiviral vector carrying the ss-galactosidase and green fluorescent reporter gene, respectively, transgene expression, self-renewal, and differentiation capabilities were assessed 2 and 14 weeks later. Transduction with the lentiviral vector resulted in higher efficiencies than with the MoMuLV-based vector (mean, 97.7 +/- 1.4% versus 80.2 +/- 5.4%; p = .02). Transgene expression was maintained with lentiviral-transduced cells (94.6 +/- 2.6%) but decreased over 14 weeks in culture with onco-retroviral-transduced cells (48.3 +/- 3.9%). The self-renewal capability of these cells and their ability to undergo osteogenic, adipogenic, and myogenic differentiation was unimpaired after transduction with either vector. Finally, clonal expansion of lentivirally modified cells was expanded over 20 population doublings with maintenance of multiline age differentiation capacity. These results suggest that hfMSCs may be suitable targets for ex vivo genetic manipulation with onco-retroviral or lentiviral vectors without affecting their stem cell properties.
Cell Differentiation↗
Recent developments in fetal medicine.
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Female↗
Antenatal and postnatal brain magnetic resonance imaging in muscle-eye-brain disease.
BACKGROUND: Muscle-eye-brain disease (MEB) is a rare autosomal recessive disorder characterized by congenital muscular dystrophy, structural eye abnormalities, and type II lissencephaly. Previous reports of brain abnormalities on magnetic resonance images (MRIs) in MEB have been in children older than 1 year. OBJECTIVE: To describe serial antenatal and postnatal brain MRIs in a child with MEB. DESIGN: Case report. PATIENT: We report a 2-year-old white boy with genetically confirmed MEB. Antenatal MRIs at 25 and 35 weeks' gestation showed posterior ventriculomegaly but no cortical dysplasia. A postnatal brain MRI at age 1 week showed frontal cortical dysplasia and abnormal signal intensity within the frontal white matter. A brain MRI at 8 months showed bilateral frontoparietal polymicrogyria. All images demonstrated flattening of the pons and mild hypoplasia of the inferior vermis. The child had no weakness, and muscle involvement was only suspected when the serum creatine kinase level was found to be elevated at age 8 months. CONCLUSION: Cortical dysplasia in MEB may not be evident until several postnatal months; therefore, if MEB is suspected, brain MRI performed in the first few months of life should be interpreted with caution.
Brain↗
Fetal cystoscopy in the management of fetal obstructive uropathy: experience in a single European centre.
OBJECTIVE: To audit diagnostic and therapeutic fetal cystoscopy for suspected posterior urethral valves (PUV). METHODS: In 13 fetuses, (14-28 weeks) the bladder was entered with a 1.3 mm embryo-fetoscope and intravesical findings documented. In 10 fetuses, an attempt was made to treat the obstruction by saline hydro-ablation (n = 4) and/or guide-wire passage (n = 9). Renal function was assessed post-natally at 10 to 34 months. RESULTS: The bladder wall was visualised in 12/13 cases and the bladder neck in 11; in 10 cases the upper urethra was entered, and the obstruction visualised in five. PUV were 'seen' in 4/9 confirmed cases, but also in one case of urethral atresia, while in two others the degree of resistance to guide-wire passage suggested atresia or prune belly. Therapeutic attempts were technically successful, at least initially, in 6/10 cases. Of the five cases with confirmed PUV and normal fetal urinary electrolytes, two have acceptable renal function at follow-up. Hydro-ablation in one case resulted in resolution of sonographic signs of obstruction, and ablated valves were confirmed post-natally. CONCLUSIONS: Semi-rigid fetal cystoscopy allows entry into the upper urethra in most obstructive uropathies, although bladder neck angulation precludes visualisation of the site of obstruction in the majority. Guide-wire passage or hydro-ablation may allow relatively atraumatic ablation of PUV in utero without the chronic bladder decompression associated with vesico-amniotic shunting. However, current technical limitations need to be overcome, possibly by the use of flexible or angled fetoscopes, before the role of cystoscopic treatment can be formally evaluated.
Cystoscopy↗
Distal urinary obstruction.
Despite the sound experimental basis and initial promise of early animal models, the results of antenatal intervention have been disappointing, with high rates of misdiagnosis of urethral valves, complications from vesicoamniotic shunting, perinatal mortality, and long-term renal impairment and bladder dysfunction in survivors. The recent development of a cystoscopic approach might obviate some of these problems, but to date the procedure been limited by technical difficulty in negotiating the urethrovesical angle. Overcoming these difficulties through equipment modifications might allow definitive testing of whether or not alleviating distal urinary obstruction in utero is beneficial.
Animals↗
Fetal renal impairment.
Renal function in utero deals chiefly with urine production rather than the excretion of metabolites, which are cleared by the placenta. Fetal renal impairment (FRI) in bilateral renal disease thus presents as oligohydramnios or anhydramnios; this can lead to lung hypoplasia and early neonatal death. As in the adult, FRI can be divided into prerenal, renal and postrenal causes. Causes of prerenal FRI include intrauterine growth restriction, unbalanced intertwin transfusion in monochorionic twins and maternal drug ingestion. Bilateral renal agenesis, multicystic dysplasia and both the autosomal dominant and recessive forms of polycystic kidney disease are examples of renal causes, whereas postrenal etiologies are usually caused by lower urinary tract obstruction (LUTO). When both kidneys are affected and there is severe mid-trimester oligohydramnios, the prognosis is poor. Although animal studies have shown that prolonged LUTO leads to lung hypoplasia and renal damage, and that decompression of the fetal kidney in early pregnancy restores fetal pulmonary and renal function, the value of fetal therapy such as vesico-amniotic shunting remains controversial, with a high procedure-related complication rate and a high incidence of end-stage renal failure in childhood. Fetal cystoscopic treatment of posterior urethral valves in utero may obviate some of these difficulties but remains an investigational procedure.
Animals↗
CD34+ cells from first-trimester fetal blood are enriched in primitive hemopoietic progenitors.
OBJECTIVE: The purpose of this study was to investigate whether purified CD34(+) cells from first-trimester fetal blood are a source of primitive and committed hemopoietic progenitors. STUDY DESIGN: CD34(+) cells from first-trimester fetal blood and term cord blood were assayed for committed hemopoietic progenitor cells, high proliferative potential colony-forming cells, and long-term culture-initiating cells. RESULTS: First-trimester CD34(+) cells that were compared with cells at term generated fewer hemopoietic progenitor cells and fewer high proliferative potential colony-forming cells with lower recloning efficiency(P <.001). First-trimester CD34(+) cells tended to contain more long-term culture-initiating cells, both in bulk cultures and by limiting dilution analysis. The ratio between committed and primitive progenitors was 3 in the first-trimester and 20 in the term cord blood, respectively. CONCLUSION: First-trimester fetal blood is enriched in primitive (compared with committed) hemopoietic progenitors and may be an advantageous source of stem cells for prenatal therapy.
Antigens, CD34↗
Characterization of first trimester fetal erythroblasts for non-invasive prenatal diagnosis.
Isolating fetal erythroblasts from first trimester maternal blood offers a promising non-invasive alternative for prenatal diagnosis. The aim of this study was to characterize the biological properties of first trimester primitive erythroblasts to facilitate their enrichment from first trimester maternal blood. Primitive erythroblasts were the predominant cell type until 12 weeks gestation, after which time their numbers declined steeply; 100% were epsilon-globin-positive versus <0.06% definitive erythroblasts. Buoyant densities of first trimester fetal erythroblasts ranged from 1.077 to 1.130 g/ml, and optimal recoveries were obtained with Percoll 1118. Although primitive erythroblasts carried a negative surface charge and were resistant to NH(4)Cl lysis, these properties had only a limited role in fetal cell enrichment. Immunophenotyping showed that primitive, like definitive, erythroblasts were GPA+, CD47+, CD45- and CD35-, whereas CD71 expression was weak/undetectable on primitive erythroblasts but strongly positive on 100% of definitive erythroblasts; primitive erythroblasts were also CD36- whereas definitive erythroblasts were CD36+. We therefore used CD45/GPA selection of Percoll 1118-separated cells to demonstrate successful enrichment of male epsilon-globin-positive fetal erythroblasts from model mixtures, and as proof of principle from some first trimester maternal blood samples. Fetal cell enrichment protocols based on first trimester epsilon-globin-positive primitive erythroblasts may allow reliable enrichment of fetal cells from maternal blood for early non-invasive prenatal diagnosis of genetic disorders.
Ammonium Chloride↗
Expandability of haemopoietic progenitors in first trimester fetal and maternal blood: implications for non-invasive prenatal diagnosis.
OBJECTIVES: Selective amplification of rare fetal cells in maternal blood is a potential strategy for non-invasive prenatal diagnosis. We assessed the proliferative potential of first trimester fetal progenitors compared to maternal ones. METHODS: Fetal and maternal haemopoietic progenitors were cultured separately and in two model mixtures: (i) co-cultures of male fetal nucleated cells mixed with maternal nucleated cells and (ii) co-cultures of malefetal CD34+ cells with maternal CD34+ cells. Cell origin was detected by X-Y fluorescence in situ hybridisation (FISH) RESULTS: The frequency of haemopoietic progenitors in first trimester fetal blood (predominantly CFU-GEMM) differed from those in peripheral blood from pregnant women (predominantly BFU-e). First trimester haemopoietic progenitors formed larger colonies (p=0.0001) and their haemoglobinisation was accelerated compared to those of maternal origin (p<0.001). CD34+ fetal haemopoietic progenitor cells could be expanded four times more than their maternal counterparts (median 235.8-fold, range 174.0-968.0 vs 71.9-fold, range 41.1-192.0; p=0.003). While selective expansion of fetal cells was not observed in the mononuclear cell model, the CD34+ cell rare event mixtures produced a 463.2-fold (range 128.0-2915.0) expansion of fetal cells. CONCLUSION: Selective expansion of first trimester fetal haemopoietic progenitors may be useful for amplifying fetal cells from maternal blood.
Antigens, CD34↗
High transduction efficiency of circulating first trimester fetal mesenchymal stem cells: potential targets for in utero ex vivo gene therapy.
We recently reported the existence of fetal mesenchymal stem cells in first trimester fetal blood. Here we demonstrate that fetal mesenchymal stem cells from as early as eight weeks of gestation can be retrovirally transduced with 99% efficiency without selection. Circulating fetal mesenchymal stem cells are known to readily expand and differentiate into multiple tissue types both in vitro and in vivo, and might be suitable vehicles for prenatal gene delivery. With advances in early fetal blood sampling techniques, we suggest that genetic disorders causing irreversible damage before birth could be treated in utero in the late first/early second trimester by genetically manipulated autologous fetal stem cells.
Female↗