56 research outputs found
Systemic thrombotic microangiopathy associated with complement pathway mutations in living donor kidney transplant: case report
El síndrome urémico hemolítico (SUH) se caracteriza por la presencia de anemia hemolítica,plaquetopenia e insuficiencia renal aguda. Si bien se distingue clásicamente en típico o infeccioso y atípico, es menester reconocer situacionesclínicas en las que se pone de manifiesto, como por ejemplo, embarazo, puerperio inmediato,tumores, trasplante, drogas, etc., condiciones clínicas que han sido denominadas amplificadoras del complemento.La recurrencia postrasplante del síndrome urémico hemolítico atípico (SUHa) ha sido descrita en porcentajes variables en pacientes con mutaciones del factor H, factor B, factor I y C3, y gen de la trombomodulina, en reportes de casos aislados. Se presenta el caso de una paciente con enfermedad renal crónica (ERC) secundaria a agenesia renal, receptora preemptive de un riñón de donante vivo relacionado que presentó disfunción del injerto renal secundaria a microangiopatía trombótica, asociado acomplicación neurológica, hemorragias, disfunción orgánica múltiple y óbito. Se describen los hallazgos del estudio genético yanatomopatológico de necropsia.Hemolytic uremic syndrome (HUS) is characterized by the presence of hemolytic anemia, thrombocytopenia and acute kidney injury. Although it is usually distinguished as typical or infectious and atypical, it is necessary to recognize clinical situations in which it is revealed, such as pregnancy, immediate postpartum period, tumors, transplantation, drugs, etc., i.e. clinical conditions that have been called complement-amplifying conditions. Post-transplantation recurrence of atypical hemolytic uremic syndrome (aHUS) has been described in variable percentages in patients with mutations of factor H, factor B, factor I and C3, and thrombomodulin gene, in reports of isolated cases. We present the case of a patient with chronic kidney disease (CKD) secondary to renal agenesis, a preemptive recipient of a related living donor kidney, which presented renal graft dysfunction secondary to thrombotic microangiopathy, associated with neurological complications, hemorrhages, multiple organ dysfunction and death. The findings of the genetic and pathological autopsy study are described.Fil: Gutierrez, Roberto. Fundación Favaloro; ArgentinaFil: Fortunato, Rita Marcela. Fundación Favaloro; ArgentinaFil: Vigliano, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Espinoza, Álvaro. Fundación Favaloro; ArgentinaFil: Nava, Alison. Fundación Favaloro; ArgentinaFil: De Francesco, Juan. Fundación Favaloro; ArgentinaFil: Raffaele, Pablo Miguel. Fundación Favaloro; Argentin
Growth of Neanderthal infants from Krapina (120-130 ka), Croatia
Modern humans have a slow and extended period of childhood growth but to what extent this ontogenetic pathway was present in Neanderthals is debated. Dental development, linked to the duration of somatic growth across modern primates, is the main source for information about growth and development in a variety of fossil primates, including humans. Studies of Neanderthal permanent teeth report a pace of development either similar to recent humans or relatively accelerated. Neanderthal milk teeth, which form and emerge before permanent teeth, provide an opportunity to determine which pattern was present at birth. Here we present a comparative study of the prenatal and early postnatal growth of five milk teeth from three Neanderthals (120,000-130,000 years ago) using virtual histology. Results reveal regions of their milk teeth formed quickly before birth, and over a relatively short period of time after birth. Tooth emergence commenced towards the earliest end of the eruption schedules displayed by extant human children. Advanced dental development is consistent with expectations for Neanderthal infant feeding
Cell Lineage Analysis of the Mammalian Female Germline
Fundamental aspects of embryonic and post-natal development, including maintenance of the mammalian female germline, are largely unknown. Here we employ a retrospective, phylogenetic-based method for reconstructing cell lineage trees utilizing somatic mutations accumulated in microsatellites, to study female germline dynamics in mice. Reconstructed cell lineage trees can be used to estimate lineage relationships between different cell types, as well as cell depth (number of cell divisions since the zygote). We show that, in the reconstructed mouse cell lineage trees, oocytes form clusters that are separate from hematopoietic and mesenchymal stem cells, both in young and old mice, indicating that these populations belong to distinct lineages. Furthermore, while cumulus cells sampled from different ovarian follicles are distinctly clustered on the reconstructed trees, oocytes from the left and right ovaries are not, suggesting a mixing of their progenitor pools. We also observed an increase in oocyte depth with mouse age, which can be explained either by depth-guided selection of oocytes for ovulation or by post-natal renewal. Overall, our study sheds light on substantial novel aspects of female germline preservation and development
On the Effect of Nb on the Microstructure and Properties of Next Generation Polycrystalline Powder Metallurgy Ni-Based Superalloys
Abstract
The effect of Nb on the properties and microstructure of two novel powder metallurgy (P/M) Ni-based superalloys was evaluated, and the results critically compared with the Rolls-Royce alloy RR1000. The Nb-containing alloy was found to exhibit improved tensile and creep properties as well as superior oxidation resistance compared with both RR1000 and the Nb-free variant tested. The beneficial effect of Nb on the tensile and creep properties was due to the microstructures obtained following the post-solution heat treatments, which led to a higher γ′ volume fraction and a finer tertiary γ′ distribution. In addition, an increase in the anti-phase-boundary energy of the γ′ phase is also expected with the addition of Nb, further contributing to the strength of the material. However, these modifications in the γ′ distribution detrimentally affect the dwell fatigue crack-growth behavior of the material, although this behavior can be improved through modified heat treatments. The oxidation resistance of the Nb-containing alloy was also enhanced as Nb is believed to accelerate the formation of a defect-free Cr2O3 scale. Overall, both developmental alloys, with and without the addition of Nb, were found to exhibit superior properties than RR1000.This work was supported by the Rolls-Royce/EPSRC Strategic Partnership under EP/H022309/1, EP/H500375/1 and EP/ M005607/1
Differences in the Properties and Mirna Expression Profiles between Side Populations from Hepatic Cancer Cells and Normal Liver Cells
AIMS: Because hepatic cancer stem cells (HCSCs) are believed to derive from the conversion of hepatic normal stem cells (HNSCs), the identification of the differences that distinguish HCSCs from HNSCs is important. METHODS: The HCC model was established in F344 rats by DEN induction. Using FACS analysis, side population cells from HCC (SP-HCCs) were isolated from the epithelial-like cells of HCC tissues, and the side population cells from normal liver (SP-NLCs) were isolated from syngeneic normal liver cells. The expression of stem cell markers was detected in both freshly isolated and amplified subpopulations. After induction with HGF, the differentiation of each subpopulation was analyzed by detection of early and late liver markers. In vivo, the biological characteristics of SP-HCCs and SP-NLCs were analyzed by repairing injured livers or forming tumors in nude mice. In addition, the expression of miRNAs was examined in both populations by miRNA array and QRT-PCR. RESULTS: SP-NLCs and SP-HCCs were 4.30±0.011% and 2.100±0.010% of the whole population, respectively. Both SP-NLCs and SP-HCCs displayed greater expression of stem cell markers (CD133 and EpCAM) than NSP-NLCs and NSP-HCCs, respectively (P<0.01), both after fresh isolation and amplification. Upon HGF induction, SP-NLCs generated many ALB positive cells and few CK-7 positive cells, but NSP-NLCs could generate only ALB positive cells. In contrast, SP-HCCs gave rise to only AFP positive cells. As few as 5 × 10⁵ SP-NLCs were capable of repairing liver injury, while the same number of NSP-NLCs could not repair the liver. Furthermore, only 1 × 10⁴ SP-HCCs were necessary to initiate a tumor, while NSP-HCCs could not form a tumor. Compared to SP-NLCs, 68 up-regulated and 10 down-regulated miRNAs were present in SP-HCCs (P<0.01). CONCLUSION: Based on the decisive roles of some miRNAs in the genesis of HCSCs, miRNAs may contribute to the different characteristics that distinguish SP-HCCs from SP-NLCs
Comprehensive study of 28 individuals with SIN3A-related disorder underscoring the associated mild cognitive and distinctive facial phenotype
Witteveen-Kolk syndrome (OMIM 613406) is a recently defined neurodevelopmental syndrome caused by heterozygous loss-of-function variants in SIN3A. We define the clinical and neurodevelopmental phenotypes related to SIN3A-haploinsufficiency in 28 unreported patients. Patients with SIN3A variants adversely affecting protein function have mild intellectual disability, growth and feeding difficulties. Involvement of a multidisciplinary team including a geneticist, paediatrician and neurologist should be considered in managing these patients. Patients described here were identified through a combination of clinical evaluation and gene matching strategies (GeneMatcher and Decipher). All patients consented to participate in this study. Mean age of this cohort was 8.2 years (17 males, 11 females). Out of 16 patients ≥ 8 years old assessed, eight (50%) had mild intellectual disability (ID), four had moderate ID (22%), and one had severe ID (6%). Four (25%) did not have any cognitive impairment. Other neurological symptoms such as seizures (4/28) and hypotonia (12/28) were common. Behaviour problems were reported in a minority. In patients ≥2 years, three were diagnosed with Autism Spectrum Disorder (ASD) and four with Attention Deficit Hyperactivity Disorder (ADHD). We report 27 novel variants and one previously reported variant. 24 were truncating variants; three were missense variants and one large in-frame gain including exons 10–12
Intronic ATTTC repeat expansions in STARD7 in familial adult myoclonic epilepsy linked to chromosome 2
Familial Adult Myoclonic Epilepsy (FAME) is characterised by cortical myoclonic tremor
usually from the second decade of life and overt myoclonic or generalised tonic-clonic seizures.
Four independent loci have been implicated in FAME on chromosomes (chr) 2, 3, 5
and 8. Using whole genome sequencing and repeat primed PCR, we provide evidence that
chr2-linked FAME (FAME2) is caused by an expansion of an ATTTC pentamer within the first
intron of STARD7. The ATTTC expansions segregate in 158/158 individuals typically affected
by FAME from 22 pedigrees including 16 previously reported families recruited worldwide.
RNA sequencing from patient derived fibroblasts shows no accumulation of the AUUUU or
AUUUC repeat sequences and STARD7 gene expression is not affected. These data, in
combination with other genes bearing similar mutations that have been implicated in FAME,
suggest ATTTC expansions may cause this disorder, irrespective of the genomic locus
involvedSupplementary Information:
Supplementary Data 1;
Supplementary Data 2;
Reporting Summary.NHMRC;
Women’s and Children’s Hospital Research Foundation;
Muir Maxwell Trust;
Epilepsy Society;
The European Fund for Regional Development;
The province of Friesland, Dystonia Medical Research Foundation;
Stichting Wetenschapsfonds Dystonie Vereniging;
Fonds Psychische Gezondheid;
Phelps Stichting;
The Italian Ministry of Health;
Istituto Superiore di Sanità, Italy;
Undiagnosed Disease Network Italy;
The Fondation maladies rares, University Hospital Essen and
UK Department of Health’s NIHR.https://www.nature.com/ncommspm2020Neurolog
Evidence of spatial clustering of childhood acute lymphoblastic leukemia cases in Greater Mexico City: report from the Mexican Inter-Institutional Group for the identification of the causes of childhood leukemia
BackgroundA heterogeneous geographic distribution of childhood acute lymphoblastic leukemia (ALL) cases has been described, possibly, related to the presence of different environmental factors. The aim of the present study was to explore the geographical distribution of childhood ALL cases in Greater Mexico City (GMC).MethodsA population-based case-control study was conducted. Children <18 years old, newly diagnosed with ALL and residents of GMC were included. Controls were patients without leukemia recruited from second-level public hospitals, frequency-matched by sex, age, and health institution with the cases. The residence address where the patients lived during the last year before diagnosis (cases) or the interview (controls) was used for geolocation. Kulldorff’s spatial scan statistic was used to detect spatial clusters (SCs). Relative risks (RR), associated p-value and number of cases included for each cluster were obtained.ResultsA total of 1054 cases with ALL were analyzed. Of these, 408 (38.7%) were distributed across eight SCs detected. A relative risk of 1.61 (p<0.0001) was observed for the main cluster. Similar results were noted for the remaining seven ones. Additionally, a proximity between SCs, electrical installations and petrochemical facilities was observed.ConclusionsThe identification of SCs in certain regions of GMC suggest the possible role of environmental factors in the etiology of childhood ALL
Heterozygous Variants in KMT2E Cause a Spectrum of Neurodevelopmental Disorders and Epilepsy.
We delineate a KMT2E-related neurodevelopmental disorder on the basis of 38 individuals in 36 families. This study includes 31 distinct heterozygous variants in KMT2E (28 ascertained from Matchmaker Exchange and three previously reported), and four individuals with chromosome 7q22.2-22.23 microdeletions encompassing KMT2E (one previously reported). Almost all variants occurred de novo, and most were truncating. Most affected individuals with protein-truncating variants presented with mild intellectual disability. One-quarter of individuals met criteria for autism. Additional common features include macrocephaly, hypotonia, functional gastrointestinal abnormalities, and a subtle facial gestalt. Epilepsy was present in about one-fifth of individuals with truncating variants and was responsive to treatment with anti-epileptic medications in almost all. More than 70% of the individuals were male, and expressivity was variable by sex; epilepsy was more common in females and autism more common in males. The four individuals with microdeletions encompassing KMT2E generally presented similarly to those with truncating variants, but the degree of developmental delay was greater. The group of four individuals with missense variants in KMT2E presented with the most severe developmental delays. Epilepsy was present in all individuals with missense variants, often manifesting as treatment-resistant infantile epileptic encephalopathy. Microcephaly was also common in this group. Haploinsufficiency versus gain-of-function or dominant-negative effects specific to these missense variants in KMT2E might explain this divergence in phenotype, but requires independent validation. Disruptive variants in KMT2E are an under-recognized cause of neurodevelopmental abnormalities
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