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BACKGROUND: In this study we aimed to describe the morphological and pathogenetic differences between tracheal agenesis and tracheal atresia, which are not clearly distinguished from each other in the literature, and to contribute thereby to the understanding and management of these conditions. Both tracheal agenesis and tracheal atresia represent rare disorders of still unknown aetiology that cannot be detected by prenatal ultrasound. If the affected foetuses survive until birth these conditions result in respiratory failure and in futile attempts to rescue the infant's life. RESULTS: Autopsies and genetic analyses, including singleton or trio exome sequencing, were performed on five neonates/foetuses with tracheal agenesis and three foetuses with tracheal atresia. Tracheal agenesis was characterized by absence of the sublaryngeal trachea and presence of a bronchooesophageal fistula and by pulmonary isomerism and occurred as an isolated malformation complex or as part of a VACTERL association. Special findings were an additional so-called 'pig bronchus' and a first case of tracheal agenesis with sirenomelia. Tracheal atresia presenting with partial obliteration of its lumen and persistence of a fibromuscular streak resulted in CHAOS. This condition was associated with normal lung lobulation and single, non-VACTERL type malformations. Trio ES revealed a novel variant of MAPK11 in one tracheal agenesis case. Its involvement in tracheooesophageal malformation is herein discussed, but remains hypothetical. CONCLUSION: Tracheal agenesis and tracheal atresia represent different disease entities in terms of morphology, pathogenesis and accompanying anomalies due to a primary developmental and secondary disruptive possibly vascular disturbance, respectively.
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Deformidades Congênitas dos Membros , Traqueia/anormalidades , Recém-Nascido , Gravidez , Feminino , Humanos , Constrição Patológica , Esôfago/anormalidadesRESUMO
BACKGROUND: Autosomal-recessive SLOS is caused by mutations in the DHCR7 gene. It is defined as a highly variable complex of microcephaly with intellectual disability, characteristic facies, hypospadias, and polysyndactyly. Syndrome diagnosis is often missed at prenatal ultrasound and fetal autopsy METHODS: We performed autopsies and DHCR7 gene analyses in eight fetuses suspected of having SLOS and measured cholesterol values in long-term formalin-fixed tissues of an additional museum exhibit RESULTS: Five of the nine fetuses presented classical features of SLOS, including four cases with atrial/atrioventricular septal defects and renal anomalies, and one with additional bilateral renal agenesis and a Dandy-Walker cyst. These cases allowed for diagnosis at autopsy and subsequent SLOS diagnosis in two siblings. Two fetuses were mildly affected and two fetuses showed additional holoprosencephaly. These four cases and the exhibit had escaped diagnosis at autopsy. The case with bilateral renal agenesis presented a novel combination of a null allele and a putative C-terminus missense mutation in the DHCR7 gene CONCLUSIONS: In view of the discrepancy between the prevalence of SLOS among newborns and the carrier frequency of a heterozygous DHCR7 gene mutation, the syndrome-specific internal malformation pattern may be helpful not to miss SLOS diagnosis in fetuses at prenatal ultrasound and fetal autopsy.
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Síndrome de Smith-Lemli-Opitz/diagnóstico , Síndrome de Smith-Lemli-Opitz/fisiopatologia , Anormalidades Múltiplas , Autopsia/métodos , Síndrome de Dandy-Walker , Feminino , Feto/metabolismo , Defeitos dos Septos Cardíacos , Humanos , Mutação/genética , Mutação de Sentido Incorreto/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Fenótipo , Gravidez , Síndrome de Smith-Lemli-Opitz/genéticaRESUMO
In the absence of ligands, the nuclear receptor PPARß/δ recruits the NCOR and SMRT corepressors, which form complexes with HDAC3, to canonical target genes. Agonistic ligands cause dissociation of corepressors and enable enhanced transcription. Vice versa, synthetic inverse agonists augment corepressor recruitment and repression. Both basal repression of the target gene ANGPTL4 and reinforced repression elicited by inverse agonists are partially insensitive to HDAC inhibition. This raises the question how PPARß/δ represses transcription mechanistically. We show that the PPARß/δ inverse agonist PT-S264 impairs transcription initiation by decreasing recruitment of activating Mediator subunits, RNA polymerase II, and TFIIB, but not of TFIIA, to the ANGPTL4 promoter. Mass spectrometry identifies NCOR as the main PT-S264-dependent interactor of PPARß/δ. Reconstitution of knockout cells with PPARß/δ mutants deficient in basal repression results in diminished recruitment of NCOR, SMRT, and HDAC3 to PPAR target genes, while occupancy by RNA polymerase II is increased. PT-S264 restores binding of NCOR, SMRT, and HDAC3 to the mutants, resulting in reduced polymerase II occupancy. Our findings corroborate deacetylase-dependent and -independent repressive functions of HDAC3-containing complexes, which act in parallel to downregulate transcription.
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Proteína 4 Semelhante a Angiopoietina/genética , Histona Desacetilases/genética , Complexos Multiproteicos/genética , PPAR beta/genética , Transcrição Gênica , Linhagem Celular , Humanos , Ligantes , Espectrometria de Massas , Correpressor 1 de Receptor Nuclear/genética , Correpressor 2 de Receptor Nuclear/genética , Regiões Promotoras Genéticas/genética , RNA Polimerase II/genética , Fator de Transcrição TFIIB/genética , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: It was tested whether the difference in carcinogenesis between noxa and human papillomavirus (HPV)-driven head and neck squamous cell carcinoma (HNSCC) is associated with a variation in genomic instability. METHODS: Conventional and molecular cytogenetics in HPV-positive and HPV-negative HNSCC cell lines. RESULTS: Numerical aneuploidy determined by multicolor fluorescence in situ hybridization and DNA ploidy was very similar for both entities with most chromosomes being present either in quadruplicate or triplicate, and only few are still diploid with, however, a striking similarity in the overall pattern. A clear difference was seen concerning the translocations formed, with no difference in the total amount but with a significantly higher genomic instability of HPV-positive cell lines at chromosome 3 as compared to HPV-negative cells. CONCLUSION: The different processes of carcinogenesis of HPV-positive and HPV-negative HNSCC appear to result in a similar pattern of numerical but a clear difference in structural chromosomal aberrations.
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Aberrações Cromossômicas , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/virologia , Infecções por Papillomavirus/complicações , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/virologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologiaRESUMO
Resumen: Los estudiantes que cursan el internado profesional de fonoaudiologia experimentan situaciones de estrés y agotamiento propias de esta acti vidad, pudiendo presentar burnout académico (BA), ya que el contacto con usuarios reales, la exigencia académica y las acciones propias de un contexto laboral son caracteristicas de la práctica profesional. El objeti vo del presente estudio es determinar la existencia del burnout acadé mico y la asociación con variables sociodemográficas en los estudiantes de 5to año de fonoaudiología. Se aplicó un cuestionario a 47 sujetos de internado profesional para recopilar antecedentes personales, académi cos y sociales. Luego, para evaluar el burnout académico, se aplicó el Maslach Burnout Inventory-Student Survey. Los estudiantes evaluados no presentan el síndrome, aunque el factor cansancio emocional se presentó con más altos puntajes. Tampoco existen diferencias entre los puntajes del síndrome para los estudiantes que realizan su práctica en las áreas de Salud y Educación. Las variables explicativas del alto cansancio emocional en este estudio son el sexo masculino, pertenecer a sector urbano y aumento de consumo de taba co. El estudio del BA es importante para tomar medidas preventivas en el transcurso de la vida universitaria para garantizar a futuro el com promiso y mejor desempeño por parte de los estudiantes que realizan su práctica profesional.
Abstract: Students who attend internship of speech language pathology expe rience situations of stress and exhaustion characteristic of this activ ity, being able to present academic burnout, due to the contact with real users, the academic requirement and the own actions of a work context, which are characteristics of the internship. The objective of this study was to determine the existence of academic burnout and its association with sociodemographic variables in the 5th year stu dents of speech language pathology. A questionnaire was applied to 47 intern students in order to gather personal, academic and social backgrounds. After to evaluate the academic burnout, the Maslach Burnout Inventory - Student Survey was applied. The students evaluated did not present the syndrome, although the emotional fatigue factor was presented with higher scores. There are also no differences in the scores of the syndrome for students who did their practice in both health and education setting. The explana tory variables of high emotional fatigue in this study were male sex, belonging to the urban sector and increased tobacco consumption. The BA study is important to take preventive measures over the university life to ensure future commitment and better performance by students who perform their professional practice.
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Humanos , Masculino , Feminino , Adulto , Estudantes/psicologia , Esgotamento Profissional/etiologia , Esgotamento Profissional/epidemiologia , Fonoaudiologia , Prática Profissional , Universidades , Esgotamento Profissional/diagnóstico , Esgotamento Profissional/psicologia , Modelos Logísticos , Chile , Inquéritos e Questionários , Patologia da Fala e Linguagem , Despersonalização , Desempenho Acadêmico , Internato e ResidênciaRESUMO
Adolescence is a period characterized by continued improvements in inhibitory control, and this persisting immaturity is believed to interact with affective/motivational behavior to generate the impulsive and risk-taking behavior evidenced at this time. Puberty is a central event of adolescence that has been shown to influence affective/motivational behavior. However, despite plausible mechanisms by which puberty might influence inhibitory control, researchers have yet to test this possibility rigorously. Thus, we designed a study to examine the unique role of pubertal maturation, independent of age, in the development of inhibitory control. In order to minimize age-related variability while maximizing pubertal status variability, we recruited 78 participants (34 F) whose ages narrowly spanned the mean age of gonadarche for each sex (F: ages 11-13, M: ages 12-14). Two complementary measures were used to assess pubertal status: (1) circulating blood serum testosterone and estradiol levels reflecting internal manifestations of pubertal maturation, and (2) Tanner staging by a trained nurse reflecting pubertal maturation's external manifestations. Inhibitory control was assessed using the antisaccade task, and findings were adjusted for the potential effect of age. Results revealed no association between testosterone levels and error rates or response latencies in either sex. In girls, estradiol levels were not associated with error rates, but were associated with faster response latencies. There was similarly no association between Tanner status and error rates, although girls in more advanced pubertal stages showed faster response latencies. Power analyses indicate that findings of a lack of association did not reflect limited statistical power. Thus, in a study designed to isolate the effects of pubertal maturation independent of age, both external and internal indices of pubertal maturation converged to indicate that age-related improvements in cold antisaccade performance are independent of pubertal maturation.
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Fixação Ocular/fisiologia , Puberdade/fisiologia , Movimentos Sacádicos/fisiologia , Autocontrole , Maturidade Sexual/fisiologia , Adolescente , Criança , Estradiol/sangue , Feminino , Humanos , Masculino , Testosterona/sangueRESUMO
INTRODUCTION: The prevalence of neural tube defects worldwide is 1â-â2 per 1000 neonates. Neural tube defects result from a disturbance of neurulation in the 3rd or 4th week of development and thus represent the earliest manifestation of organ malformation. Neural tube defects (NTD) are classified into cranial dysraphism leading to anencephaly or meningoencephalocele and spinal dysraphism with or without meningomyelocele. In isolated form they have multifactorial causes, and the empirical risk of recurrence in Central Europe is 2%. As associated malformations they tend to occur sporadically, and in monogenic syndromes they follow Mendelian inheritance patterns with a high risk of recurrence. PATIENTS: Autopsies were performed on 68 fetuses following a prenatal diagnosis of NTD and induced abortion. RESULTS: The incidence of NTDs in our autopsied fetuses was 8% and 11% in fetuses with malformations. The percentage of fetuses with anencephaly, encephalocele or spina bifida was 24, 18, and 60%*, respectively. Analysis of the sex distribution showed a female preponderance in cranial dysraphisms but the sex distribution of spina bifida cases was equal. The extent and localization of NTDs varied, with lumbosacral cases clearly predominating. The proportion of isolated, associated and syndromic neural tube defects was 56, 23.5 and 20.6% respectively. In the majority of syndromes, the neural tube defect represented a not previously observed syndromic feature. CONCLUSION: The high proportion of NTDs with monogenic background underlines the importance of a syndrome oriented fetal pathology. At the very least it requires a thourough photographic and radiographic documentation of the fetal phenotype to enable the genetic counsellor to identify a syndromic disorder. This is necessary to determine the risk of recurrence, arrange confirming mutation analyses and offer targeted prenatal diagnosis in subsequent pregnancies.
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We report the case of a 26 year-old patient presenting with a persistent leukocytosis and CML-like marrow but no evidence of a BCR/ABL1 fusion. Molecular cytogenetics revealed that a portion of the ETV6 locus was inserted into the ABL1 locus. An ETV6/ABL1 fusion transcript could subsequently be confirmed. The patient was started on imatinib and went into complete cytomorphological remission. QRT-PCR measurements showed a 4 log reduction of the ETV6/ABL1 fusion. 15 months later, the disease transformed into ALL and the patient expired. Thus, an ETV6/ABL1 fusion positive MPN has the potential to transform very rapidly into ALL.
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In this study, lymphoblastoid cells derived from a 83-year old individual with a 15year history of progressive presenile dementia, were used to generate iPS cells, employing episomal plasmids expressing OCT4, SOX2, LIN28, L-MYC and a p53 shRNA. The individual was homozygous for the APOE4 allele. The resulting iPS cells had a normal karyotype, retained the APOE4/4 genotype, expressed pluripotency markers, were free of genomically integrated plasmids, and could be differentiated into cell type representatives from the three germ layers in vitro.
Assuntos
Apolipoproteína E4/genética , Demência/patologia , Células-Tronco Pluripotentes Induzidas/citologia , Idoso de 80 Anos ou mais , Linfócitos B/citologia , Sequência de Bases , Diferenciação Celular , Linhagem Celular , Reprogramação Celular , Demência/genética , Corpos Embrioides/citologia , Corpos Embrioides/metabolismo , Feminino , Genótipo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Cariótipo , Microscopia de Fluorescência , Plasmídeos/genética , Plasmídeos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
In this study, lymphoblastoid cells derived from a 79-year old individual with a history of progressive presenile dementia, were used to generate iPS cells, employing episomal plasmids expressing OCT4, SOX2, KLF4, LIN28, L-MYC and a p53 shRNA. The individual was homozygous for the APOE4 allele. The resulting iPS cells had a normal karyotype, retained the APOE4/4 genotype, expressed pluripotency markers, were free of genomically integrated plasmids, and could be differentiated into cell type representatives from the three germ layers in vitro.
Assuntos
Apolipoproteína E4/genética , Demência/patologia , Células-Tronco Pluripotentes Induzidas/citologia , Idoso , Linfócitos B/citologia , Diferenciação Celular , Linhagem Celular , Reprogramação Celular , Demência/genética , Corpos Embrioides/citologia , Corpos Embrioides/metabolismo , Genótipo , Homozigoto , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Cariótipo , Fator 4 Semelhante a Kruppel , Microscopia de Fluorescência , Plasmídeos/genética , Plasmídeos/metabolismo , Polimorfismo de Nucleotídeo Único , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Mesoaxial synostotic syndactyly, Malik-Percin type (MSSD) (syndactyly type IX) is a rare autosomal-recessive nonsyndromic digit anomaly with only two affected families reported so far. We previously showed that the trait is genetically distinct from other syndactyly types, and through autozygosity mapping we had identified a locus on chromosome 17p13.3 for this unique limb malformation. Here, we extend the number of independent pedigrees from various geographic regions segregating MSSD to a total of six. We demonstrate that three neighboring missense mutations affecting the highly conserved DNA-binding region of the basic helix-loop-helix A9 transcription factor (BHLHA9) are associated with this phenotype. Recombinant BHLHA9 generated by transient gene expression is shown to be located in the cytoplasm and the cell nucleus. Transcription factors 3, 4, and 12, members of the E protein (class I) family of helix-loop-helix transcription factors, are highlighted in yeast two-hybrid analysis as potential dimerization partners for BHLHA9. In the presence of BHLHA9, the potential of these three proteins to activate expression of an E-box-regulated target gene is reduced considerably. BHLHA9 harboring one of the three substitutions detected in MSSD-affected individuals eliminates entirely the transcription activation by these class I bHLH proteins. We conclude that by dimerizing with other bHLH protein monomers, BHLHA9 could fine tune the expression of regulatory factors governing determination of central limb mesenchyme cells, a function made impossible by altering critical amino acids in the DNA binding domain. These findings identify BHLHA9 as an essential player in the regulatory network governing limb morphogenesis in humans.
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Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Dedos/anormalidades , Mutação de Sentido Incorreto , Sindactilia/genética , Dedos do Pé/anormalidades , Sequência de Aminoácidos , Sítios de Ligação , Análise Mutacional de DNA , Dimerização , Feminino , Genes Reporter , Genótipo , Haplótipos , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Paquistão , Linhagem , Fenótipo , Ligação Proteica , Estrutura Terciária de Proteína , Alinhamento de Sequência , Turquia , Adulto JovemRESUMO
This article describes strategies for using a postpartum depression screening tool with women from two immigrant minority populations (from Yemen and from the Punjab region of India). Techniques to maximize success while working with interpreters and with women's unique cultural considerations are presented. Two case studies provide examples of challenges presented and overcome by women from each of these populations.
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Competência Cultural , Depressão Pós-Parto/diagnóstico , Depressão Pós-Parto/enfermagem , Emigrantes e Imigrantes/psicologia , Programas de Rastreamento/instrumentação , Grupos Minoritários/psicologia , Cuidado Pós-Natal/organização & administração , Características Culturais , Emigrantes e Imigrantes/estatística & dados numéricos , Feminino , Humanos , Índia/etnologia , Grupos Minoritários/estatística & dados numéricos , Estudos de Casos Organizacionais , Escalas de Graduação Psiquiátrica , Fatores Socioeconômicos , Tradução , Estados Unidos , Iêmen/etnologiaRESUMO
OBJECTIVE: To use objective, nonverbal oculomotor tasks to assess executive function and infer the neural basis of impairments in preterm children. STUDY DESIGN: Cross-sectional study of preterm children age 9-16 years (n = 69; mean gestational age 29 weeks) and full-term controls (n = 43). Tasks assessed sensorimotor function (reflexive prosaccades); resistance to peripheral distracters (fixation); response inhibition, response preparation, and execution of a voluntary saccade (antisaccades); and spatial working memory (memory-guided saccades). Group differences were analyzed using ANOVA. We used linear regression to analyze the contributions of age, sex, gestational age, and white matter category to task performance. RESULTS: Preterm children did not differ from controls on basic sensorimotor function, response inhibition, and working memory. Compared with controls, preterm children showed greater susceptibility to peripheral distracters (P = .008) and were slower to initiate an inhibitory response (P = .003). Regression models showed contributions of age and white matter category to task performance. CONCLUSIONS: Preterm children show intact basic sensorimotor function and demonstrate difficulties in processes underlying executive control, including increased distractibility and prolonged response preparation. These limitations may reflect specific neural abnormalities in fronto-subcortical executive control of behavior.
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Função Executiva/fisiologia , Movimentos Oculares/fisiologia , Recém-Nascido Prematuro/fisiologia , Adolescente , Criança , Estudos Transversais , Feminino , Humanos , Recém-Nascido , Masculino , Memória , Movimentos Sacádicos/fisiologia , Análise e Desempenho de TarefasRESUMO
We report on a triplet pregnancy of consanguineous parents with one fetus being affected by recurrent Johanson-Blizzard syndrome (JBS). At autopsy in the 35th gestational week, the affected triplet presented with an especially severe and lethal manifestation of the disorder as compared to his elder affected brother and to cases in the literature, thus exemplifying great interfamilial and intrafamilial phenotypic variability. Arhinencephaly and cystic renal dysplasia associated with urethral obstruction sequence were features not described previously in the literature. In addition to the lack of exocrine acini as the characteristic feature of JBS, the pancreas revealed a resorptive inflammatory reaction with infiltration by eosinophilic granulocytes that focally dispersed onto islets of Langerhans, thus favoring a progressive destructive rather than primary dysplastic process and possibly explaining the occurrence of diabetes mellitus in later life. JBS maps to chromosome 15q15-q21.1 and is associated with mutations in the UBR1 gene. Testing the fetus and the affected sibling revealed a homozygous truncating mutation in UBR1. The resulting absence of the UBR1 protein was confirmed by Western blot. Immunohistochemical staining using a commercial anti-UBR1 antibody demonstrated staining, presumably artifactual. This finding suggests that, until an appropriately validated antibody has been identified, this modality should not be utilized for diagnosis or confirmation of this disorder.
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Constrição Patológica/patologia , Surdez/patologia , Displasia Ectodérmica/patologia , Hidronefrose/patologia , Hipotireoidismo/patologia , Oligo-Hidrâmnio/patologia , Pancreatopatias/patologia , Doenças Vasculares Periféricas/patologia , Síndrome do Abdome em Ameixa Seca/patologia , Obstrução Uretral/patologia , Adulto , Anus Imperfurado , Pré-Escolar , Consanguinidade , Constrição Patológica/genética , Constrição Patológica/metabolismo , Surdez/genética , Surdez/metabolismo , Displasia Ectodérmica/genética , Displasia Ectodérmica/metabolismo , Evolução Fatal , Feminino , Morte Fetal , Idade Gestacional , Transtornos do Crescimento , Perda Auditiva Neurossensorial , Humanos , Hidronefrose/genética , Hidronefrose/metabolismo , Hipotireoidismo/genética , Hipotireoidismo/metabolismo , Deficiência Intelectual , Masculino , Mutação , Mucosa Nasal/metabolismo , Nariz/anormalidades , Nariz/patologia , Oligo-Hidrâmnio/genética , Oligo-Hidrâmnio/metabolismo , Pâncreas/patologia , Pancreatopatias/genética , Pancreatopatias/metabolismo , Pancreatite , Doenças Vasculares Periféricas/genética , Doenças Vasculares Periféricas/metabolismo , Gravidez , Gravidez de Trigêmeos , Síndrome do Abdome em Ameixa Seca/genética , Síndrome do Abdome em Ameixa Seca/metabolismo , Recidiva , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genética , Obstrução Uretral/genética , Obstrução Uretral/metabolismoRESUMO
INTRODUCTION: This study presents our online-teaching material within the k-MED project (Knowledge in Medical Education) at the university of Marburg. It is currently organized in five e-learning modules: cytogenetics, chromosomal aberrations, formal genetics, fundamentals of molecular diagnostics, and congenital abnormalities and syndromes. These are basic courses intended to do the educational groundwork, which will enable academic teachers to concentrate on more sophisticated topics during their lectures. METHODS: The e-learning modules have been offered to a large group of about 3300 students during four years at the Faculty of Medicine in Marburg. The group consists of science students (human biology) and medical students in the preclinical or the clinical period, respectively. Participants were surveyed on acceptance by evaluating user-tracking data and questionnaires. RESULTS AND CONCLUSION: Analysis of the evaluation data proofs the broad acceptance of the e-learning modules during eight semesters. The courses are in stable or even increasing use from winter term 2005/06 until spring term 2009. CONCLUSION: Our e-learning-model is broadly accepted among students with different levels of knowledge at the Faculty of Medicine in Marburg. If the e-learning courses are maintained thoroughly, minor adaptations can increase acceptance and usage even furthermore. Their use should be extended to the medical education of technical assistances and nurses, who work in the field of human genetics.
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Chromosomal instability (CIN) is a major hallmark of human cancer and might contribute to tumorigenesis. Genes required for the normal progression of mitosis represent potential CIN genes and, as such, are important tumour suppressors. The Chk2 kinase and its downstream targets p53 and Brca1 are tumour suppressors that have been functionally linked to the DNA damage response pathway. Here, we report a function of Chk2, independent of p53 and DNA damage, that is required for proper progression of mitosis, and for the maintenance of chromosomal stability in human somatic cells. Depletion of Chk2 or abrogation of its kinase activity causes abnormal mitotic spindle assembly associated with a delay in mitosis, which promotes the generation of lagging chromosomes, chromosome missegregation and CIN, while still allowing survival and growth. Furthermore, we have identified Brca1 as a mitotic target of the Chk2 kinase in the absence of DNA damage. Accordingly, loss of BRCA1 or its Chk2-mediated phosphorylation leads to spindle formation defects and CIN. Thus, the CHK2-BRCA1 tumour suppressor pathway is required for chromosomal stability, which might contribute to their tumour suppressor function.
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Proteína BRCA1/fisiologia , Instabilidade Cromossômica , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Supressoras de Tumor/metabolismo , Proteína BRCA1/metabolismo , Linhagem Celular , Quinase do Ponto de Checagem 2 , Humanos , Mitose , Fosforilação , Proteínas Serina-Treonina Quinases/deficiência , Transdução de Sinais , Fuso Acromático/metabolismo , Fuso Acromático/patologiaRESUMO
PURPOSE: We report a rare case of Pallister-Killian syndrome diagnosed prenatally with increased nuchal translucency during screening for trisomy 21. MATERIALS AND METHODS: Echografic and postmortem examination of the fetus, G-banded chromosome and FISH analysis on short- and long-term chorion villous sampling (CVS) culture. RESULTS AND DISCUSSION: Cytogenetic analysis revealed a supernumerary isochromosome 12p after long-term culture whereas a normal cell line was detected in short-term culture only. Sonografic examination in 17-weeks' gestation showed further increase of the NT and the additional presence of brachymelia, diaphragmatic hernia and a marked dextroposition of the heart. Termination of the pregnancy was performed. The cases of PKS karyotypically confirmed on CVS are reviewed, and cytogenetic and sonographic aspects of the prenatal diagnosis of PKS are discussed.
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Anormalidades Múltiplas/embriologia , Aberrações Cromossômicas/embriologia , Cromossomos Humanos Par 12/genética , Isocromossomos/genética , Anormalidades Múltiplas/diagnóstico por imagem , Anormalidades Múltiplas/genética , Feto Abortado , Adulto , Evolução Fatal , Feminino , Humanos , Cariotipagem , Medição da Translucência Nucal , Gravidez , Ultrassonografia Pré-NatalRESUMO
OBJECTIVES: We report on a female fetus of 24 weeks gestational age with Fine-Lubinsky syndrome (FLS), representing the 7th case published so far. METHODS: Prenatal ultrasound was performed at 22+1 weeks of gestation and thorough postmortem examination was made after termination of pregnancy. RESULTS: The diagnosis of FLS in the fetus was based on characteristic features that were already apparent in early prenatal life, such as growth deficiency, brachycephaly, flat face with associated dysmorphic signs, microstomia and cataract, while deafness and mental retardation, which are syndrome-specific functional disorders and evident only postnatally, could not be taken into account. CONCLUSIONS: This case demonstrates the diagnostic problems in fetal syndromology if syndrome-specific features are not yet recognizable and additional complications occur that had not been observed in this disorder.
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Catarata/congênito , Catarata/diagnóstico por imagem , Surdez/congênito , Deficiência Intelectual/complicações , Microstomia/diagnóstico por imagem , Síndrome de Pierre Robin/diagnóstico por imagem , Poli-Hidrâmnios/diagnóstico por imagem , Crânio/anormalidades , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/diagnóstico por imagem , Adulto , Catarata/patologia , Feminino , Humanos , Masculino , Microstomia/patologia , Síndrome de Pierre Robin/diagnóstico , Gravidez , Síndrome , Ultrassonografia Pré-NatalRESUMO
Focal dermal hypoplasia (FDH) is an X-linked dominant multisystem birth defect affecting tissues of ectodermal and mesodermal origin. Using a stepwise approach of (i) genetic mapping of FDH, (ii) high-resolution comparative genome hybridization to seek deletions in candidate chromosome areas and (iii) point mutation analysis in candidate genes, we identified PORCN, encoding a putative O-acyltransferase and potentially crucial for cellular export of Wnt signaling proteins, as the gene mutated in FDH. The findings implicate FDH as a developmental disorder caused by a deficiency in PORCN.