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Aguiar LS, Juliano GR, Silveira LAM, Oliveira MS, Torquato BGS, Juliano GR, Araújo MF, Pereira SAL, Teixeira VDPA, Ferraz MLF. Tongue development in stillborns autopsied at different gestational ages. J Pediatr (Rio J) 2018; 94:616-623. [PMID: 29112857 DOI: 10.1016/j.jped.2017.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 08/08/2017] [Accepted: 08/08/2017] [Indexed: 01/14/2023] Open
Abstract
OBJECTIVES This study aimed to analyze, through the morphometric method, the perimeter and length of the tongue, the collagen fibers, and the perimeter of blood vessels at different gestational ages and fetal weights. MATERIAL AND METHODS Tongues (n=55) of stillborns autopsied at 23-40 weeks of gestational age were macroscopically analyzed, and their length and perimeter were measured. Fifty-five tongue fragments were collected through a longitudinal section in the region that accompanies the median lingual sulcus and histologically processed. Slides were stained with picrosirius and immunolabeled with CD31 antibody. Quantification was performed on collagen fibers under polarized light, and on the perimeter of vessels with the CD31. RESULTS A positive and significant correlation of gestational age with tongue perimeter and length was found. There was a positive and significant correlation between collagen fibers and gestational age, as well as between gestational age and the perimeter of blood vessels. Between collagen fibers and fetal weight, a positive and significant increase was observed. Regarding the correlation between the perimeter of blood vessels and the fetal weight, an increase was observed. CONCLUSION As gestational age advances, there is an increase in tongue perimeter and length, in the percentage of collagen fibers, and in vascular perimeter, demonstrating that tongue formation is directly related to tongue growth and development.
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Affiliation(s)
- Laura S Aguiar
- Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | | | - Luciano A M Silveira
- Universidade Federal do Triângulo Mineiro (UFTM), Departamento de Cirurgia, Programa de Pós-Graduação em Ciências da Saúde, Uberaba, MG, Brazil.
| | | | | | | | - Márcia F Araújo
- Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, MG, Brazil
| | | | - Vicente de Paula A Teixeira
- Universidade Federal do Triângulo Mineiro (UFTM), Instituto de Ciências Biológicas e Naturais, Uberaba, MG, Brazil
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Tongue development in stillborns autopsied at different gestational ages. JORNAL DE PEDIATRIA (VERSÃO EM PORTUGUÊS) 2018. [DOI: 10.1016/j.jpedp.2017.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Stereological study of developing glomerular forms during human fetal kidney development. Pediatr Nephrol 2018; 33:817-825. [PMID: 29273971 DOI: 10.1007/s00467-017-3874-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 12/11/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Human fetal kidney development is a complex and stepwise process. The number, shape, size and distribution of glomeruli provide important information on kidney organization. The aim of this study was to quantify glomerular developing forms during human fetal kidney development using stereological methods. METHODS Kidney tissue specimens of 40 human fetuses with gestational ages ranging from 9 to 40 weeks were analyzed. Specimens were divided into eight groups based on gestational age, each corresponding to 1 lunar month. Stereological methods were used at the light microscopy level to estimate volume, surface and numerical density of the glomerular developing forms. RESULTS During gestation, nephrogenesis continually advanced, and the number of nephrons increased. Volume, surface and numerical densities of vesicular forms and S-shaped bodies decreased gradually in parallel with gradual increases in estimated stereological parameters for vascularized glomeruli. Volume density and surface density of vascularized glomeruli increased gradually during fetal kidney development, and numerical density increased until the seventh lunar month. A relative decrease in vascularized glomeruli per unit volume of cortex occurred during the last 3 lunar months. Nephrogenesis began to taper off by 32 weeks and was completed by 36 weeks of gestation. The last sample in which we observed vesicles was from a fetus aged 32 weeks, and the last sample with S-shaped bodies was from a fetus aged 36 weeks. CONCLUSIONS The present study is one of few quantitative studies conducted on human kidney development. Knowledge of normal human kidney morphogenesis during development could be important for future medical practice. Events occurring during fetal life may have significant consequences later in life.
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Development of the Human Fetal Kidney from Mid to Late Gestation in Male and Female Infants. EBioMedicine 2017; 27:275-283. [PMID: 29329932 PMCID: PMC5828465 DOI: 10.1016/j.ebiom.2017.12.016] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/27/2017] [Accepted: 12/14/2017] [Indexed: 01/03/2023] Open
Abstract
Background During normal human kidney development, nephrogenesis (the formation of nephrons) is complete by term birth, with the majority of nephrons formed late in gestation. The aim of this study was to morphologically examine nephrogenesis in fetal human kidneys from 20 to 41 weeks of gestation. Methods Kidney samples were obtained at autopsy from 71 infants that died acutely in utero or within 24 h after birth. Using image analysis, nephrogenic zone width, the number of glomerular generations, renal corpuscle cross-sectional area and the cellular composition of glomeruli were examined. Kidneys from female and male infants were analysed separately. Findings The number of glomerular generations formed within the fetal kidneys was directly proportional to gestational age, body weight and kidney weight, with variability between individuals in the ultimate number of generations (8 to 12) and in the timing of the cessation of nephrogenesis (still ongoing at 37 weeks gestation in one infant). There was a slight but significant (r2 = 0.30, P = 0.001) increase in renal corpuscle cross-sectional area from mid gestation to term in females, but this was not evident in males. The proportions of podocytes, endothelial and non-epithelial cells within mature glomeruli were stable throughout gestation. Interpretation These findings highlight spatial and temporal variability in nephrogenesis in the developing human kidney, whereas the relative cellular composition of glomeruli does not appear to be influenced by gestational age. There is spatial and temporal variability in nephrogenesis in the developing human kidney. The relative cellular composition of mature glomeruli does not appear to be influenced by gestational age. There is apparent sexual dimorphism in the growth of glomeruli during late gestation.
The number of glomeruli (filtering units of the kidneys) you are born with directly influences your life-long kidney health, therefore it is important to understand how they are formed. Between mid-pregnancy and term, there was variability between individuals in relation to the number of layers of glomeruli formed in the developing kidney, and variation in the timing of when they stopped being formed. In fully-formed glomeruli, the proportion of the different cell types in glomeruli remained constant within the developing kidneys throughout pregnancy. Female infants, but not males, exhibited an increase in the size of glomeruli from mid-pregnancy to term.
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Gerosa C, Fanni D, Faa A, Van Eyken P, Ravarino A, Fanos V, Faa G. Low vascularization of the nephrogenic zone of the fetal kidney suggests a major role for hypoxia in human nephrogenesis. Int Urol Nephrol 2017; 49:1621-1625. [DOI: 10.1007/s11255-017-1630-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 05/25/2017] [Indexed: 12/11/2022]
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Assessment of kidney function in preterm infants: lifelong implications. Pediatr Nephrol 2016; 31:2213-2222. [PMID: 26846786 DOI: 10.1007/s00467-016-3320-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 12/20/2015] [Accepted: 12/31/2015] [Indexed: 01/18/2023]
Abstract
This educational review will highlight the historical and contemporary references that establish a basic understanding of measurements of kidney function in the neonate and its relevance for the life of an individual. Importantly, the differential renal function of preterm infants relative to term infants has become paramount with the increased viability of preterm infants and the realization that kidney function is associated with gestational age. Moreover, neonatal kidney function is primarily associated with absolute renal mass and hemodynamic stability. Neonatal kidney function and its early developmental progression predict lifelong cardiovascular and renal disease risks. Validation of estimation equations of kidney function in this population has provided important reference data for other investigations and a clinical basis for prospective and longitudinal follow-up. Future research should be directed towards a better understanding of surrogate markers of kidney function from infancy through adulthood. Pediatric nephrologists should be aware of the developmental aspects of kidney function including the importance of the congenital nephron endowment and the preservation of kidney function throughout a lifetime. • Nephrogenesis occurs in utero in concert with other organ systems by branching morphogenesis, including the lungs, pancreas, and vascular tree, with over 60 % of nephrons being formed during the last trimester. • Infants born preterm before 36 weeks' gestation are in active nephrogenesis and are at increased risk of having a decreased nephron endowment from prenatal and postnatal genetic and epigenetic hazards that will impact the patient for a lifetime. • Post-natal adaptation of kidney function is directly proportional to the number of perfused nephrons, estimated by total kidney volume (TKV), mean arterial pressure (MAP), and gestational age. • Accurate measurement of glomerular filtration rate (GFR) in infants is problematic due to the unavailability of the gold standard inulin. The traditional use of creatinine to estimate GFR is unreliable in preterm infants due to its tubular reabsorption by immature kidneys and its dependence on muscle mass as an endogenous marker. Alternative endogenous markers to estimate GFR are cystatin C and beta trace protein (BTP). • Long-term follow-up of renal function in those born preterm should be life long and should include assessment of GFR, total kidney volume (TKV) relative to body surface area (BSA), and cardiovascular risks including hypertension and vascular stiffness.
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Roderick PJ, Jeffrey RF, Yuen HM, Godfrey KM, West J, Wright J. Smaller kidney size at birth in South Asians: findings from the Born in Bradford birth cohort study. Nephrol Dial Transplant 2015. [PMID: 26209714 DOI: 10.1093/ndt/gfv274] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Rates of advanced chronic kidney disease and renal replacement therapy are higher in South Asian than in white British populations. Low birth weight is also more frequent in South Asian populations and has been associated with increased risks of kidney disease, perhaps due to a reduced nephron endowment. METHODS Using ultrasound scans at 34 weeks of gestation, we measured fetal kidney dimensions (transverse and anteroposterior diameters, length and circumference) and derived volume in a random sample of 872 white British and 715 South Asian participants in the Born in Bradford cohort study. Kidney measurements were compared between ethnic groups. RESULTS Birth weight for gestational age at 40 weeks was 200 g less in South Asian babies compared with white British babies. The mean kidney volume for gestational age was 16% lower in South Asian than in white British babies [8.79 versus 10.45 cm(3), difference 1.66 cm(3) (95% confidence interval 1.40-1.93, P < 0.001)]. The difference was robust after adjustment for maternal age, socio-economic factors, marital status, body mass index, smoking and alcohol use in pregnancy, parity, baby's gender and birth weight for gestational age [adjusted difference 1.38 cm(3) (0.97-1.84), P < 0.001]. There were smaller reductions in other fetal measures. CONCLUSION South Asian babies have smaller kidneys compared with white British babies, even after adjusting for potential confounders including birth weight. This finding may contribute to increased risks of adult kidney disease in South Asian populations.
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Affiliation(s)
- Paul J Roderick
- Primary Care and Population Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Robin F Jeffrey
- Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK
| | - Ho M Yuen
- Primary Care and Population Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Keith M Godfrey
- MRC Lifecourse Epidemiology Unit and NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Jane West
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK
| | - John Wright
- Bradford Institute for Health Research, Bradford Teaching Hospitals NHS Foundation Trust, Bradford, UK
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From ureteric bud to the first glomeruli: genes, mediators, kidney alterations. Int Urol Nephrol 2014; 47:109-16. [PMID: 25201458 DOI: 10.1007/s11255-014-0784-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 07/04/2014] [Indexed: 12/23/2022]
Abstract
The development of the mammalian kidney is a complex and in part unknown process which requires interactions between pluripotential/stem cells, undifferentiated mesenchymal cells, epithelial and mesenchymal components, eventually leading to the coordinate development of multiple different specialized epithelial, endothelial and stromal cell types within the kidney architectural complexity. We will describe the embryology and molecular nephrogenetic mechanisms, a fascinating traffic of cells and tissues which takes place in five stages: (1) ureteric bud (UB) development; (2) cap mesenchyme formation; (3) mesenchymal-epithelial transition (MET); (4) glomerulogenesis and tubulogenesis; (5) interstitial cell development. In particular, we will analyze the multiple cell types involved in these dramatic events as characters moving between different worlds, from the mesenchymal to the epithelial world and back, and will start to define the multiple factors that propel these cells during their travels throughout the developing kidney. Moreover, according with the hypothesis of renal perinatal programing, we will present the results reached in the fields of immunohistochemistry and molecular biology, by means of which we can explain how a loss or excess of molecular factors governing nephrogenesis may cause the onset of pathologies of different gravity, in some cases leading to a chronic kidney disease at different times from birth.
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Dunford LJ, Sinclair KD, Kwong WY, Sturrock C, Clifford BL, Giles TC, Gardner DS. Maternal protein-energy malnutrition during early pregnancy in sheep impacts the fetal ornithine cycle to reduce fetal kidney microvascular development. FASEB J 2014; 28:4880-92. [PMID: 25077559 PMCID: PMC4216596 DOI: 10.1096/fj.14-255364] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
This paper identifies a common nutritional pathway relating maternal through to fetal protein-energy malnutrition (PEM) and compromised fetal kidney development. Thirty-one twin-bearing sheep were fed either a control (n=15) or low-protein diet (n=16, 17 vs. 8.7 g crude protein/MJ metabolizable energy) from d 0 to 65 gestation (term, ∼145 d). Effects on the maternal and fetal nutritional environment were characterized by sampling blood and amniotic fluid. Kidney development was characterized by histology, immunohistochemistry, vascular corrosion casts, and molecular biology. PEM had little measureable effect on maternal and fetal macronutrient balance (glucose, total protein, total amino acids, and lactate were unaffected) or on fetal growth. PEM decreased maternal and fetal urea concentration, which blunted fetal ornithine availability and affected fetal hepatic polyamine production. For the first time in a large animal model, we associated these nutritional effects with reduced micro- but not macrovascular development in the fetal kidney. Maternal PEM specifically impacts the fetal ornithine cycle, affecting cellular polyamine metabolism and microvascular development of the fetal kidney, effects that likely underpin programming of kidney development and function by a maternal low protein diet.—Dunford, L. J., Sinclair, K. D., Kwong, W. Y., Sturrock, C., Clifford, B. L., Giles, T. C., Gardner, D. S.. Maternal protein-energy malnutrition during early pregnancy in sheep impacts the fetal ornithine cycle to reduce fetal kidney microvascular development.
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Affiliation(s)
| | | | | | | | | | - Tom C Giles
- Advanced Data Analysis Centre, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
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Faa G, Gerosa C, Fanni D, Monga G, Zaffanello M, Van Eyken P, Fanos V. Morphogenesis and molecular mechanisms involved in human kidney development. J Cell Physiol 2011; 227:1257-68. [DOI: 10.1002/jcp.22985] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Uncharted waters: nephrogenesis and renal regeneration in fish and mammals. Pediatr Nephrol 2011; 26:1435-43. [PMID: 21336813 DOI: 10.1007/s00467-011-1795-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 01/19/2011] [Accepted: 01/24/2011] [Indexed: 12/25/2022]
Abstract
The major functions of the vertebrate kidney are the removal of metabolic waste and the balance of salt and water. These roles are fulfilled by nephrons, which generally comprise a blood filter (glomerulus) attached to an epithelial tubule. The number of nephrons in the mammalian kidney is set at the end of kidney organogenesis in the late fetal or neonatal period. Subsequent increases in nephron size and functionality then occur during postnatal growth to match increases in body mass/fluid. Because of this strategy of renal development, injuries or birth defects that reduce nephron number lead to a permanent nephron deficit and increase the risk of kidney disease. In contrast to mammals, fish kidneys continue to add nephrons throughout their lifespan. In response to renal injury, fish increase the rate of nephrogenesis, effectively replacing lost nephrons and maintaining their nephron endowment. A better understanding of the remarkable nephrogenic abilities of fish kidneys may lead to innovative ways to restore nephrogenesis in the adult mammalian kidney. This review examines our current understanding of nephrogenesis in mammals and fish and explores possible explanations for why fish, but not mammals, utilize a perpetual nephrogenesis strategy to grow and maintain their kidneys.
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Gubhaju L, Sutherland MR, Yoder BA, Zulli A, Bertram JF, Black MJ. Is nephrogenesis affected by preterm birth? Studies in a non-human primate model. Am J Physiol Renal Physiol 2009; 297:F1668-77. [PMID: 19759270 DOI: 10.1152/ajprenal.00163.2009] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nephrogenesis occurs predominantly in late gestation at a time when preterm infants are already delivered. The aims of this study were to assess the effect of preterm birth and the effect of antenatal glucocorticoid treatment on nephrogenesis. Preterm baboons, which were delivered at 125 days gestation and ventilated for up to 21 days postnatally, were compared with gestational controls. A cohort of preterm baboons that had been exposed to antenatal glucocorticoids were compared with unexposed preterm baboons. The number of glomerular generations was estimated using a medullary ray glomerular-counting method, and glomerular number was estimated using unbiased stereology. CD31 and WT-1 localization was examined using immunohistochemistry and VEGF was localized using in situ hybridization. The number of glomerular generations was not affected by preterm birth, and total glomerular numbers were within the normal range. Kidneys were significantly enlarged in preterm baboons with a significant decrease in glomerular density (number of glomeruli per gram of kidney) in the preterm kidney compared with gestational controls. Neonates exposed to antenatal steroids had an increased kidney-to-body weight ratio and also more developed glomeruli compared with unexposed controls. Abnormal glomeruli, with a cystic Bowman's space and shrunken glomerular tuft, were often present in the superficial renal cortex of both the steroid-exposed and unexposed preterm kidneys; steroid exposure had no significant effect on the proportion of abnormal glomeruli. The proportion of abnormal glomeruli in the preterm kidneys ranged from 0.2 to 18%. In conclusion, although nephrogenesis is ongoing in the extrauterine environment, our findings demonstrate that preterm birth, independent of steroid exposure, is associated with a high proportion of abnormal glomeruli in some, but not all neonatal kidneys. Whether final nephron endowment is affected in those kidneys exhibiting a high proportion of abnormal glomeruli is yet to be confirmed.
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Affiliation(s)
- Lina Gubhaju
- Dept. of Anatomy and Developmental Biology, Monash Univ., Victoria 3800, Australia
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Bagby SP. Developmental Origins of Renal Disease: Should Nephron Protection Begin at Birth? Clin J Am Soc Nephrol 2009; 4:10-3. [DOI: 10.2215/cjn.06101108] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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