Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 15 de 15
Filter
1.
iScience ; 27(6): 109909, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38812539

ABSTRACT

Small intestine (SI) maturation during early life is pivotal in preventing the onset of gut diseases. In this study we interrogated the milestones of SI development by gene expression profiling and ingenuity pathway analyses. We identified a set of cytokines as main regulators of changes observed across different developmental stages. Upon cytokines stimulation, with IFNγ as the most contributing factor, human fetal organoids (HFOs) increase brush border gene expression and enzyme activity as well as trans-epithelial electrical resistance. Electron microscopy revealed developed brush border and loss of fetal cell characteristics in HFOs upon cytokine stimulation. We identified T cells as major source of IFNγ production in the fetal SI lamina propria. Co-culture of HFOs with T cells recapitulated the major effects of cytokine stimulation. Our findings underline pro-inflammatory cytokines derived from T cells as pivotal factors inducing functional SI maturation in vivo and capable of modulating the barrier maturation of HFOs in vitro.

2.
Cochrane Database Syst Rev ; 5: CD014715, 2024 05 09.
Article in English | MEDLINE | ID: mdl-38721874

ABSTRACT

BACKGROUND: Prenatal ultrasound is widely used to screen for structural anomalies before birth. While this is traditionally done in the second trimester, there is an increasing use of first-trimester ultrasound for early detection of lethal and certain severe structural anomalies. OBJECTIVES: To evaluate the diagnostic accuracy of ultrasound in detecting fetal structural anomalies before 14 and 24 weeks' gestation in low-risk and unselected pregnant women and to compare the current two main prenatal screening approaches: a single second-trimester scan (single-stage screening) and a first- and second-trimester scan combined (two-stage screening) in terms of anomaly detection before 24 weeks' gestation. SEARCH METHODS: We searched MEDLINE, EMBASE, Science Citation Index Expanded (Web of Science), Social Sciences Citation Index (Web of Science), Arts & Humanities Citation Index and Emerging Sources Citation Index (Web of Science) from 1 January 1997 to 22 July 2022. We limited our search to studies published after 1997 and excluded animal studies, reviews and case reports. No further restrictions were applied. We also screened reference lists and citing articles of each of the included studies. SELECTION CRITERIA: Studies were eligible if they included low-risk or unselected pregnant women undergoing a first- and/or second-trimester fetal anomaly scan, conducted at 11 to 14 or 18 to 24 weeks' gestation, respectively. The reference standard was detection of anomalies at birth or postmortem. DATA COLLECTION AND ANALYSIS: Two review authors independently undertook study selection, quality assessment (QUADAS-2), data extraction and evaluation of the certainty of evidence (GRADE approach). We used univariate random-effects logistic regression models for the meta-analysis of sensitivity and specificity. MAIN RESULTS: Eighty-seven studies covering 7,057,859 fetuses (including 25,202 with structural anomalies) were included. No study was deemed low risk across all QUADAS-2 domains. Main methodological concerns included risk of bias in the reference standard domain and risk of partial verification. Applicability concerns were common in studies evaluating first-trimester scans and two-stage screening in terms of patient selection due to frequent recruitment from single tertiary centres without exclusion of referrals. We reported ultrasound accuracy for fetal structural anomalies overall, by severity, affected organ system and for 46 specific anomalies. Detection rates varied widely across categories, with the highest estimates of sensitivity for thoracic and abdominal wall anomalies and the lowest for gastrointestinal anomalies across all tests. The summary sensitivity of a first-trimester scan was 37.5% for detection of structural anomalies overall (95% confidence interval (CI) 31.1 to 44.3; low-certainty evidence) and 91.3% for lethal anomalies (95% CI 83.9 to 95.5; moderate-certainty evidence), with an overall specificity of 99.9% (95% CI 99.9 to 100; low-certainty evidence). Two-stage screening had a combined sensitivity of 83.8% (95% CI 74.7 to 90.1; low-certainty evidence), while single-stage screening had a sensitivity of 50.5% (95% CI 38.5 to 62.4; very low-certainty evidence). The specificity of two-stage screening was 99.9% (95% CI 99.7 to 100; low-certainty evidence) and for single-stage screening, it was 99.8% (95% CI 99.2 to 100; moderate-certainty evidence). Indirect comparisons suggested superiority of two-stage screening across all analyses regarding sensitivity, with no significant difference in specificity. However, the certainty of the evidence is very low due to the absence of direct comparisons. AUTHORS' CONCLUSIONS: A first-trimester scan has the potential to detect lethal and certain severe anomalies with high accuracy before 14 weeks' gestation, despite its limited overall sensitivity. Conversely, two-stage screening shows high accuracy in detecting most fetal structural anomalies before 24 weeks' gestation with high sensitivity and specificity. In a hypothetical cohort of 100,000 fetuses, the first-trimester scan is expected to correctly identify 113 out of 124 fetuses with lethal anomalies (91.3%) and 665 out of 1776 fetuses with any anomaly (37.5%). However, 79 false-positive diagnoses are anticipated among 98,224 fetuses (0.08%). Two-stage screening is expected to correctly identify 1448 out of 1776 cases of structural anomalies overall (83.8%), with 118 false positives (0.1%). In contrast, single-stage screening is expected to correctly identify 896 out of 1776 cases before 24 weeks' gestation (50.5%), with 205 false-positive diagnoses (0.2%). This represents a difference of 592 fewer correct identifications and 88 more false positives compared to two-stage screening. However, it is crucial to acknowledge the uncertainty surrounding the additional benefits of two-stage versus single-stage screening, as there are no studies directly comparing them. Moreover, the evidence supporting the accuracy of first-trimester ultrasound and two-stage screening approaches primarily originates from studies conducted in single tertiary care facilities, which restricts the generalisability of the results of this meta-analysis to the broader population.


Subject(s)
Pregnancy Trimester, First , Pregnancy Trimester, Second , Ultrasonography, Prenatal , Female , Humans , Pregnancy , Bias , Congenital Abnormalities/diagnostic imaging , Sensitivity and Specificity , Ultrasonography, Prenatal/statistics & numerical data
3.
Laryngoscope ; 2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38676421

ABSTRACT

OBJECTIVES: Down syndrome (DS) is associated with airway abnormalities including a narrowed trachea. It is uncertain whether this narrowed trachea in DS is a consequence of deviant fetal development or an acquired disorder following endotracheal intubation after birth. This study aimed to compare the tracheal morphology in DS and non-DS fetuses using microfocus computed tomography (micro-CT). METHODS: Twenty fetal samples were obtained from the Dutch Fetal Biobank and divided into groups based on gestational age. Micro-CT images were processed to analyze tracheal length, volume, and cross-sectional area (CSA). RESULTS: Mean tracheal length and tracheal volume were similar in DS and non-DS fetuses for all gestational age groups. Mean, minimum, and maximal tracheal CSA were statistically significantly increased in the single DS fetus in the group of 21-24 weeks of gestation, but not in other gestational age groups. In 90% of all studied fetuses, the minimum tracheal CSA was located in the middle third of the trachea. CONCLUSION: Tracheal development in DS fetuses was similar to non-DS fetuses between 13 and 21 weeks of gestation. This suggests that the narrowed tracheal diameter in DS children may occur later in fetal development or results from postnatal intubation trauma. The narrowest part of the trachea is in majority of DS and non-DS fetuses the middle third. LEVEL OF EVIDENCE: Level 3 Laryngoscope, 2024.

4.
Dev Cell ; 58(24): 2826-2835, 2023 Dec 18.
Article in English | MEDLINE | ID: mdl-38113849

ABSTRACT

Recent studies of human embryos and fetuses have advanced our understanding not only of basic biology but also of health and disease, through a combination of detailed three-dimensional (3D) morphology and processes such as gene expression, cellular decision-making and differentiation, and epigenetics during the various phases of human development and growth. Large-scale research initiatives focusing on these topics have been initiated during the last decade, all of which depend on biobanks that provide high-quality images of human embryonic and fetal morphology, as well as on high-quality collections of tissue samples that are obtained and stored appropriately. In this perspective, we describe our experience in establishing the Dutch Fetal Biobank to present the framework and workflow of the biobank, provide a brief discussion of the main legal and ethical aspects involved in establishing a pre-natal tissue bank, and present the preliminary data on the first 329 donated specimens.


Subject(s)
Biological Specimen Banks , Biomedical Research , Humans , Epigenomics , Fetus , Reference Standards
5.
Article in English | MEDLINE | ID: mdl-37641670

ABSTRACT

Background: In non-glaucomatous eyes, many factors impact intraocular pressure (IOP) reduction following phacoemulsification. This study aimed to determine the relationship between changes in IOP and alterations in anterior chamber biometric measurements using the Pentacam Scheimpflug anterior segment imaging system before and after uneventful phacoemulsification in non-glaucomatous eyes. Methods: This prospective interventional study included patients with ages of 20 - 80 years, no known systemic diseases, and visually significant cataracts necessitating phacoemulsification with posterior chamber intraocular lens implantation. The preoperative and two-month postoperative IOPs were measured using a Goldmann applanation tonometer, and the iridocorneal angle (ICA) in four quadrants (superior, inferior, nasal, and temporal), anterior chamber depth (ACD), and anterior chamber volume (ACV) were measured using the Pentacam. Results: Forty-two eyes of 42 patients with a mean (standard deviation [SD]) age of 56.8 (10.7) years were included; 22 (52%) were men and 20 (48%) were women. The eyes demonstrated statistically significant changes in postoperative IOP, ACD, ACV, and in widening of the ICA (all P < 0.05), with a mean (SD) IOP reduction of 4.5 (2.7) mmHg, ACD deepening of 0.7 (0.6) mm, ACV increase of 33.2 (21.1) mm3, and ICA widening of 7.5o (6.4o), 12.4o (7.7o), 9.1o (7.1o), and 11.5o (6.1o) in the superior, inferior, temporal, and nasal quadrants, respectively. A significant positive correlation was detected between pre- and postoperative IOP (r = + 0.58; P < 0.001) and between pre- and postoperative ACD (r = + 0.50; P < 0.001). Significant negative correlations were detected between preoperative ACV and changes in ACV (r = - 0.42; P < 0.001) and between preoperative ICA and changes in ICA (r = - 0.02; P = 0.001). However, no significant correlations were observed between the changes in IOP and patient age (r = + 0.001; P = 0.957) and axial length of the eye (r = + 0.13; P = 0.221), or changes in ICA (r = - 0.01; P = 0.945), ACD (r = + 0.01; P = 0.945), and ACV (r = - 0.12; P = 0.599). Conclusions: We observed a significant reduction in IOP, widening of the ICA, and increases in ACD and ACV after phacoemulsification; however, there was no significant correlation between changes in IOP and other biometric variables. Further studies are required to determine the exact mechanisms underlying these effects.

6.
Eur Radiol Exp ; 7(1): 28, 2023 06 05.
Article in English | MEDLINE | ID: mdl-37271766

ABSTRACT

BACKGROUND: This study aimed to assess the feasibility of postmortem ultra-high-field magnetic resonance imaging (UHF-MRI) to study fetal musculoskeletal anatomy and explore the contribution of variation in iodine and formaldehyde (paraformaldehyde, PFA) treatment of tissue. METHODS: Seven upper extremities from human fetuses with gestational ages of 19 to 24 weeks were included in this experimental study, approved by the Medical Research Ethics Committee. The specimens were treated with various storage (0.2-4% PFA) and staining (Lugol's solution) protocols and the wrist joint was subsequently imaged with 7.0 T UHF-MRI. Soft-tissue contrast was quantified by determining regions of interest within a chondrified carpal bone (CCB) from the proximal row, the triangular fibrocartilage (TFC), and the pronator quadratus muscle (PQM) and calculating the contrast ratios (CRs) between mean signal intensities of CCB to TFC and CCB to PQM. RESULTS: UHF-MRI showed excellent soft-tissue contrast in different musculoskeletal tissues. Increasing storage time in 4% PFA, CRs decreased, resulting in a shift from relatively hyperintense to hypointense identification of the CCB. Storage in 0.2% PFA barely influenced the CRs over time. Lugol's solution caused an increase in CRs and might have even contributed to the inversion of the CRs. CONCLUSIONS: UHF-MRI is a feasible technique to image musculoskeletal structures in fetal upper extremities and most successful after short storage in 4% PFA or prolonged storage in 0.2% PFA. The use of Lugol's solution is not detrimental on soft-tissue MRI contrast and therefore enables effectively combining UHF-MRI with contrast-enhanced micro-computed tomography using a single preparation of the specimen. RELEVANCE STATEMENT: UHF-MRI can be performed after CE-micro-CT to take advantage of both techniques. KEY POINTS: • UHF-MRI is feasible to study human fetal cartilaginous and ligamentous anatomy. • Storage in low PFA concentrations (i.e., 0.2%) improves soft-tissue contrast in UHF-MRI. • Limited preservation time in high concentrations of PFA improves soft-tissue contrast in UHF-MRI. • Prior staining with Lugol's solution does not reduce soft-tissue contrast in UHF-MRI.


Subject(s)
Fetus , Wrist Joint , Humans , X-Ray Microtomography/methods , Fetus/diagnostic imaging , Wrist Joint/diagnostic imaging , Muscle, Skeletal , Magnetic Resonance Imaging/methods
7.
Br J Radiol ; 96(1145): 20220744, 2023 Apr 01.
Article in English | MEDLINE | ID: mdl-36802835

ABSTRACT

OBJECTIVES: Adult spleens show extensive morphological variation, with a reported prevalence of 40-98% clefts (also called notches or fissures) on the splenic surface and 10-30% accessory spleens at autopsy. It is hypothesised that both anatomical variants result from a complete or partial failure of multiple splenic primordia to fuse to the main body. According to this hypothesis, fusion of the spleen primordia is completed after birth and spleen morphological variations are often explained as stagnation of spleen development at the foetal stage. We tested this hypothesis by studying early spleen development in embryos, and compared foetal and adult spleen morphology. METHODS AND MATERIALS: We assessed 22 embryonic, 17 foetal and 90 adult spleens on the presence of clefts using histology, micro-CT and conventional post-mortem CT-scans, respectively. RESULTS: The spleen primordium was observed as a single mesenchymal condensation in all embryonic specimens. The number of clefts varied from 0 to 6 in foetuses, compared to 0-5 in adults. We found no correlation between foetal age and number of clefts (R2 = 0.004). The independent samples Kolmogorov-Smirnov test showed no significant difference in the total number of clefts between adult and foetal spleens (p = 0.068). CONCLUSION: We found no morphological evidence for a multifocal origin or a lobulated developmental stage of the human spleen. ADVANCES IN KNOWLEDGE: Our findings show that splenic morphology is highly variable, independent of developmental stage and age. We suggest to abandon the term "persistent foetal lobulation" and to regard splenic clefts, regardless of their number or location, as normal variants.


Subject(s)
Anatomic Variation , Spleen , Adult , Humans , Spleen/diagnostic imaging , Spleen/pathology , Autopsy , Gestational Age , X-Ray Microtomography
8.
Pediatr Radiol ; 53(4): 632-639, 2023 04.
Article in English | MEDLINE | ID: mdl-36169668

ABSTRACT

Over the last few years, fetal postmortem microfocus computed tomography (micro-CT) imaging has increased in popularity for both diagnostic and research purposes. Micro-CT imaging could be a substitute for autopsy, particularly in very early gestation fetuses for whom autopsy can be technically challenging and is often unaccepted by parents. This article provides an overview of the latest research in fetal postmortem micro-CT imaging with a focus on diagnostic accuracy, endovascular staining approaches, placental studies and the reversibility of staining. It also discusses new methods that could prove helpful for micro-CT of larger fetuses. While more research is needed, contrast-enhanced micro-CT has the potential to become a suitable alternative to fetal autopsy. Further research using this novel imaging tool could yield wider applications, such as its practise in imaging rare museum specimens.


Subject(s)
Fetus , Placenta , Female , Pregnancy , Humans , Autopsy/methods , Gestational Age , Placenta/diagnostic imaging , Fetus/diagnostic imaging , X-Ray Microtomography/methods , Magnetic Resonance Imaging/methods
9.
Semin Cell Dev Biol ; 131: 78-92, 2022 11.
Article in English | MEDLINE | ID: mdl-35282997

ABSTRACT

Due to advancements in ultrasound techniques, the focus of antenatal ultrasound screening is moving towards the first trimester of pregnancy. The early first trimester however remains in part, a 'black box', due to the size of the developing embryo and the limitations of contemporary scanning techniques. Therefore there is a need for images of early anatomical developmental to improve our understanding of this area. By using new imaging techniques, we can not only obtain better images to further our knowledge of early embryonic development, but clear images of embryonic and fetal development can also be used in training for e.g. sonographers and fetal surgeons, or to educate parents expecting a child with a fetal anomaly. The aim of this review is to provide an overview of the past, present and future techniques used to capture images of the developing human embryo and fetus and provide the reader newest insights in upcoming and promising imaging techniques. The reader is taken from the earliest drawings of da Vinci, along the advancements in the fields of in utero ultrasound and MR imaging techniques towards high-resolution ex utero imaging using Micro-CT and ultra-high field MRI. Finally, a future perspective is given about the use of artificial intelligence in ultrasound and new potential imaging techniques such as synchrotron radiation-based CT to increase our knowledge regarding human development.


Subject(s)
Artificial Intelligence , Fetus , Female , Fetus/diagnostic imaging , Humans , Infant, Newborn , Magnetic Resonance Imaging/methods , Pregnancy , Prenatal Diagnosis/methods
10.
Development ; 147(21)2020 11 05.
Article in English | MEDLINE | ID: mdl-33033118

ABSTRACT

Mitchell-Riley syndrome (MRS) is caused by recessive mutations in the regulatory factor X6 gene (RFX6) and is characterised by pancreatic hypoplasia and neonatal diabetes. To determine why individuals with MRS specifically lack pancreatic endocrine cells, we micro-CT imaged a 12-week-old foetus homozygous for the nonsense mutation RFX6 c.1129C>T, which revealed loss of the pancreas body and tail. From this foetus, we derived iPSCs and show that differentiation of these cells in vitro proceeds normally until generation of pancreatic endoderm, which is significantly reduced. We additionally generated an RFX6HA reporter allele by gene targeting in wild-type H9 cells to precisely define RFX6 expression and in parallel performed in situ hybridisation for RFX6 in the dorsal pancreatic bud of a Carnegie stage 14 human embryo. Both in vitro and in vivo, we find that RFX6 specifically labels a subset of PDX1-expressing pancreatic endoderm. In summary, RFX6 is essential for efficient differentiation of pancreatic endoderm, and its absence in individuals with MRS specifically impairs formation of endocrine cells of the pancreas head and tail.


Subject(s)
Cell Differentiation , Diabetes Mellitus/genetics , Diabetes Mellitus/pathology , Endoderm/embryology , Gallbladder Diseases/genetics , Gallbladder Diseases/pathology , Induced Pluripotent Stem Cells/pathology , Intestinal Atresia/genetics , Intestinal Atresia/pathology , Mutation/genetics , Pancreas/embryology , Regulatory Factor X Transcription Factors/genetics , Alleles , Base Sequence , Cell Differentiation/genetics , Chromatin/metabolism , Consanguinity , Diabetes Mellitus/diagnostic imaging , Embryo, Mammalian/metabolism , Embryonic Development , Family , Female , Gallbladder Diseases/diagnostic imaging , Genome, Human , Humans , Induced Pluripotent Stem Cells/metabolism , Intestinal Atresia/diagnostic imaging , Male , Pedigree , Transcription, Genetic , Transcriptome/genetics , X-Ray Microtomography
11.
Radiology ; 297(1): 32, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32779971

ABSTRACT

Online supplemental material is available for this article.


Subject(s)
Pregnancy, Ectopic/diagnostic imaging , X-Ray Microtomography , Adult , Contrast Media , Female , Humans , Pregnancy , Pregnancy, Ectopic/surgery , Ultrasonography
12.
Aktuelle Urol ; 50(3): 274-279, 2019 Jul.
Article in German | MEDLINE | ID: mdl-29518819

ABSTRACT

INTRODUCTION: Urothelial carcinoma of the urinary bladder is a tumour of advanced age. The demographic change increases the number of very old patients ( > 80 years) subjected to TUR-B. MATERIAL AND METHODS: In a retrospective analysis, perioperative complications in 89 patients (> 80 years), who underwent a transurethral resection of the bladder between 2013 and 2016 in our department, were recorded and evaluated using the Clavien-Dindo grading system. RESULTS: Mean patient age was 87 years (82 - 94). 81 patients (91 %) were treated with oral anticoagulants (32 × ASA, 24 × NOACs, 25 × Marcumar). A histological examination revealed no tumour in 25/89 (28 %) patients, pTa in 28/89 (31 %), pT1 in 22/89 (25 %) and pT2 or higher in 14/89 patients (16 %), respectively. A total of 36/89 (40 %) patients experienced complications according to the Clavien-Dindo classification. 21/89 (23 %) of patients had a prolonged bladder irrigation due to macrohaematuria, 5/89 (6 %) needed surgical reintervention. 14 (12.4 %) patients needed a blood transfusion, 6 (5.3 %) of them preoperatively. According to the Clavien-Dindo classification, 4/89 (4 %) patients were graded as I, 21/89 (24 %) as II, 5/89 (6 %) as IIb and 3/89 (3 %) as IVa, respectively. Three patients (3 %) died postoperatively (Clavien-Dindo V). One of them died as a result of aspiration pneumonia (86 y, ASA IV), one as a result of pulmonary embolism (90 y, ASA IV) and one as a result of multiorgan failure (84 y, ASA III). In multivariate analyses, a tumour stage > T2 was confirmed as a significant predictor of the occurrence of postoperative complications (odds ratio of 9.541 (95 % CI 1.14 - 84.67 p = 0.032). For oral anticoagulants the odds ratio was 4.10 (95 % CI, 41.00 - 1.23, p = 0.050). CONCLUSION: Overall, the data show that a TUR-B is feasible in patients > 80 years with an increased complication rate in comparison to younger patients. Prolonged macrohaematuria and a high transfusion rate are attributable to the high percentage of orally anticoagulated patients.


Subject(s)
Carcinoma, Transitional Cell/surgery , Endoscopy/methods , Intraoperative Complications/classification , Postoperative Complications/classification , Urinary Bladder Neoplasms/surgery , Urinary Bladder/surgery , Age Factors , Aged, 80 and over , Carcinoma, Transitional Cell/mortality , Carcinoma, Transitional Cell/pathology , Cause of Death , Feasibility Studies , Female , Humans , Intraoperative Complications/etiology , Intraoperative Complications/mortality , Male , Neoplasm Staging , Postoperative Complications/etiology , Postoperative Complications/mortality , Retrospective Studies , Urinary Bladder/pathology , Urinary Bladder Neoplasms/mortality , Urinary Bladder Neoplasms/pathology
13.
J Ophthalmic Vis Res ; 12(4): 368-373, 2017.
Article in English | MEDLINE | ID: mdl-29090044

ABSTRACT

PURPOSE: To study changes in flap thickness made with two different microkeratome heads across different corneal locations using anterior segment optical coherence tomography (OCT). METHODS: In this prospective, non-randomized, consecutive case series, subjects who had their laser in-situ keratomileusis (LASIK) flaps made using 90 µm (MSU90) or 130 µm (MSU130) disposable M2 microkeratome heads were examined using OCT. The measurements were performed at three locations (central and 2.5 mm to either side) at 1 day, 1 week, and 1 month postoperatively. RESULTS: The central flap thickness was 123 ± 15, 130 ± 14, and 127 ± 13 µm, respectively, at 1 day, 1 week, and 1 month postoperatively in the MSU90 group (41 eyes) and 142 ± 20, 147 ± 19, and 143 ± 15 µm, respectively, in the MSU130 group (47 eyes). At 1 month, peripheral flap thickness was 161 ± 17 and 159 ± 13 µm, respectively, at 2.5 mm to the right and left of corneal center in the MSU90 group. The corresponding figures were 170 ± 14 and 167 ± 13 µm, respectively, in the MSU130 group. There was a statistically significant difference between the two groups at all locations (P < 0.001). No statistically significant change in flap thickness was detected in either group at any assessment time. There was a partial positive correlation (after controlling for preoperative manifest refractive spherical equivalent) between central flap thickness and preoperative ultrasound central pachymetry (r = 0.739, P = 0.036) in the MSU90 group but not in the MSU130 group. CONCLUSION: Using OCT, changes in flap thickness were minimal in the first month after LASIK. Flap thickness correlated strongly with central corneal thickness if a 90 µm head was used.

14.
Med Hypotheses ; 80(6): 728-31, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23541771

ABSTRACT

The isocitrate dehydrogenase 1 (IDH1) mutation occurs in high frequency in glioma and secondary glioblastoma (GBM). Mutated IDH1 produces the oncometabolite 2-hydroxyglutarate rather than α-ketoglutarate or isocitrate. The oncometabolite is considered to be the major cause of the association between the IDH1 mutation and gliomagenesis. On the other hand, the IDH1 mutation in GBM is associated with prolonged patient survival. This association is not well understood yet but IDH1 involvement in epigenetic silencing of O-6-methylguanine-DNA methyltransferase (MGMT), a DNA repair enzyme is considered to be an important mechanism. However, it was shown recently that the IDH1 mutation and MGMT silencing are independent prognostic factors. Here, we hypothesize that the IDH1 mutation reduces the capacity to produce NADPH and thus reduces the capacity to scavenge reactive oxygen species that are generated during irradiation and chemotherapy. IDH1 activity is responsible for two-thirds of the NADPH production capacity in normal brain, whereas the IDH1 mutation reduces this capacity by almost 40%. Therefore, we hypothesize that the reduced NADPH production capacity due to the IDH1 mutation renders GBM cells more vulnerable to irradiation and chemotherapy thus prolonging survival of the patients.


Subject(s)
DNA Modification Methylases/physiology , DNA Repair Enzymes/physiology , Glioma/genetics , Glioma/mortality , Isocitrate Dehydrogenase/genetics , NADP/biosynthesis , Tumor Suppressor Proteins/physiology , Chemoradiotherapy , DNA Modification Methylases/genetics , DNA Repair Enzymes/genetics , Gene Silencing/physiology , Glioma/metabolism , Glioma/therapy , Humans , Isocitrate Dehydrogenase/metabolism , Models, Biological , Mutation/genetics , NADP/metabolism , Reactive Oxygen Species/metabolism , Tumor Suppressor Proteins/genetics
15.
J Matern Fetal Neonatal Med ; 25(11): 2209-15, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22524683

ABSTRACT

OBJECTIVE: The F-box protein Fbxw8 is a cofactor of Cullin 7 (Cul7), which regulates protein transfer to the proteasome and cell growth. Cul7 or Fbxw8 deficiency is associated with intrauterine growth restriction (IUGR) due to abnormal placental development leading to poor oxygen supply to the fetus. We studied the role of hypoxia for Fbxw8 and Cul7 expression in trophoblastic cells. METHODS: Immunomagnetic bead-separated extravillous trophoblast (EVT) and villous trophoblast (VT) and trophoblast cell lines were incubated with 1 or 8% O(2). Fbxw8 and Cul7 expression was determined in IUGR versus matched control placentas. RESULTS: Fbxw8 was expressed uniformly in trophoblasts, whereas Cul7 expression was most prominent in trophoblast cell lines. Hypoxia reduced expression of Cul7 and Fbxw8 in all trophoblastic cells, except for villous trophoblasts. In vivo, Cul7 and Fbxw8 were detected in syncytiotrophoblast cells, VT, and EVT cells. Although no significant changes in expression levels of Fbxw8 or Cul7 were noted in IUGR compared with control placentas, Fbxw8 expression correlated negatively with gestational age in the control, but not in the IUGR group. CONCLUSION: Fbxw8 and Cul7 expression reveals a complex regulation in trophoblastic cells. Our findings suggest that dysregulation of Cul7 and Fbxw8 expression might affect trophoblast turnover in IUGR.


Subject(s)
Cullin Proteins/genetics , F-Box Proteins/genetics , Fetal Growth Retardation/genetics , Oxygen/pharmacology , Trophoblasts/drug effects , Adult , Cells, Cultured , Cohort Studies , Cullin Proteins/metabolism , F-Box Proteins/metabolism , Female , Fetal Growth Retardation/metabolism , Fetal Growth Retardation/pathology , Gene Expression Regulation/drug effects , Gestational Age , Humans , Infant, Newborn , Male , Oxygen/metabolism , Pregnancy , Trophoblasts/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...