1,581 research outputs found
Evaluación de la cronología dentaria en grupos wichi, toba y criollos del Gran Chaco (provincia de Formosa)
Se realizó el análisis de la cronología de erupción dentaria como una evaluación de maduración funcional en individuos pertenecientes a comunidades wichí, toba y crillas del Gran Chaco (provincia de Formosa, Argentina). Se tuvieron en cuenta los elementos dentarios presentes en cada hemiarcada izquierda y el orden de erupción. El objetivo del presente trabajo fue examinar el comportamiento de estas variables en la población infantil de ambos sexos de las distintas comunidades. La muestra estuvo integrada por 159 individuos entre 6 y 12 años. La metodología aplicada fue la del conteo de las piezas dentarias individuales. Los datos fueron volcados en una ficha odontológica pertinente. Se analizó comparativamente el orden de erupción en cada muestra investigada. Resultados: a) diferencias de erupción entre los wichí, toba y criollos; b) alteración en el orden de erupción, en el segundo premolar y los segundos molares y c) variación de erupción de las niñas con respecto a los varones. Concluimos que los grupos pertenecientes a la misma zona geográfica, pero con distinto nivel socioeconómico, muestran diferencias en la cronología dentaria, lo cual estaría indicando una influencia ambiental sobre el determinante genético
A polymorphism in a let-7 microRNA binding site of KRAS in women with endometriosis.
Endometriosis is found in 5-15% of women of reproductive age and is more frequent in relatives of women with the disease. Activation of KRAS results in de novo endometriosis in mice, however, activating KRAS mutations have not been identified in women. We screened 150 women with endometriosis for a polymorphism in a let-7 microRNA (miRNA) binding site in the 3'-UTR of KRAS and detected a KRAS variant allele in 31% of women with endometriosis as opposed to 5% of a large diverse control population. KRAS mRNA and protein expression were increased in cultured endometrial stromal cells of women with the KRAS variant. Increased KRAS protein was due to altered miRNA binding as demonstrated in reporter assays. Endometrial stromal cells from women with the KRAS variant showed increased proliferation and invasion. In a murine model, endometrial xenografts containing the KRAS variant demonstrated increased proliferation and decreased progesterone receptor levels. These findings suggest that an inherited polymorphism of a let-7 miRNA binding site in KRAS leads to abnormal endometrial growth and endometriosis. The LCS6 polymorphism is the first described genetic marker of endometriosis risk
Dermatoglífos en enfermedades cardíacas
Las enfermedades genéticas corresponden a un grupo heterogéneo de afecciones que en su etiología presentan un significativo componente genético. Ello puede ser alguna alteración en un solo gen, en varios genes (poligenes) o en muchos genes (cromosomas). La alteración genética puede producir directamente la enfermedad (por ejemplo, la hemofilia) o interactuar con factores ambientales (ejemplo, la predisposición en la etiología de hipertensión arterial). Un diagnóstico posible de realizar, es la asociación de dermatoglifos palmares y digitales con patología de origen génico. Los mismos están formados por elevaciones lineales de la epidermis, llamadas crestas donde desembocan las glándulas sudoríparas y separadas entre sí por finos surcos, describiendo complejas configuraciones presentes solo en primates y ciertas especies de marsupiales arborícolas.Facultad de Ciencias Naturales y Muse
Dermatoglífos en enfermedades cardíacas
Las enfermedades genéticas corresponden a un grupo heterogéneo de afecciones que en su etiología presentan un significativo componente genético. Ello puede ser alguna alteración en un solo gen, en varios genes (poligenes) o en muchos genes (cromosomas). La alteración genética puede producir directamente la enfermedad (por ejemplo, la hemofilia) o interactuar con factores ambientales (ejemplo, la predisposición en la etiología de hipertensión arterial). Un diagnóstico posible de realizar, es la asociación de dermatoglifos palmares y digitales con patología de origen génico. Los mismos están formados por elevaciones lineales de la epidermis, llamadas crestas donde desembocan las glándulas sudoríparas y separadas entre sí por finos surcos, describiendo complejas configuraciones presentes solo en primates y ciertas especies de marsupiales arborícolas.Facultad de Ciencias Naturales y Muse
Dermatoglífos en enfermedades cardíacas
Las enfermedades genéticas corresponden a un grupo heterogéneo de afecciones que en su etiología presentan un significativo componente genético. Ello puede ser alguna alteración en un solo gen, en varios genes (poligenes) o en muchos genes (cromosomas). La alteración genética puede producir directamente la enfermedad (por ejemplo, la hemofilia) o interactuar con factores ambientales (ejemplo, la predisposición en la etiología de hipertensión arterial). Un diagnóstico posible de realizar, es la asociación de dermatoglifos palmares y digitales con patología de origen génico. Los mismos están formados por elevaciones lineales de la epidermis, llamadas crestas donde desembocan las glándulas sudoríparas y separadas entre sí por finos surcos, describiendo complejas configuraciones presentes solo en primates y ciertas especies de marsupiales arborícolas.Facultad de Ciencias Naturales y Muse
Radiographers supporting radiologists in the interpretation of screening mammography: a viable strategy to meet the shortage in the number of radiologists.
BackgroundAn alternative approach to the traditional model of radiologists interpreting screening mammography is necessary due to the shortage of radiologists to interpret screening mammograms in many countries.MethodsWe evaluated the performance of 15 Mexican radiographers, also known as radiologic technologists, in the interpretation of screening mammography after a 6 months training period in a screening setting. Fifteen radiographers received 6 months standardized training with radiologists in the interpretation of screening mammography using the Breast Imaging Reporting and Data System (BI-RADS) system. A challenging test set of 110 cases developed by the Breast Cancer Surveillance Consortium was used to evaluate their performance. We estimated sensitivity, specificity, false positive rates, likelihood ratio of a positive test (LR+) and the area under the subject-specific Receiver Operating Characteristic (ROC) curve (AUC) for diagnostic accuracy. A mathematical model simulating the consequences in costs and performance of two hypothetical scenarios compared to the status quo in which a radiologist reads all screening mammograms was also performed.ResultsRadiographer's sensitivity was comparable to the sensitivity scores achieved by U.S. radiologists who took the test but their false-positive rate was higher. Median sensitivity was 73.3 % (Interquartile range, IQR: 46.7-86.7 %) and the median false positive rate was 49.5 % (IQR: 34.7-57.9 %). The median LR+ was 1.4 (IQR: 1.3-1.7 %) and the median AUC was 0.6 (IQR: 0.6-0.7). A scenario in which a radiographer reads all mammograms first, and a radiologist reads only those that were difficult for the radiographer, was more cost-effective than a scenario in which either the radiographer or radiologist reads all mammograms.ConclusionsGiven the comparable sensitivity achieved by Mexican radiographers and U.S. radiologists on a test set, screening mammography interpretation by radiographers appears to be a possible adjunct to radiologists in countries with shortages of radiologists. Further studies are required to assess the effectiveness of different training programs in order to obtain acceptable screening accuracy, as well as the best approaches for the use of non-physician readers to interpret screening mammography
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
Comparison of histological delineations of medial temporal lobe cortices by four independent neuroanatomy laboratories
The medial temporal lobe (MTL) cortex, located adjacent to the hippocampus, is crucial for memory and prone to the accumulation of certain neuropathologies such as Alzheimer's disease neurofibrillary tau tangles. The MTL cortex is composed of several subregions which differ in their functional and cytoarchitectonic features. As neuroanatomical schools rely on different cytoarchitectonic definitions of these subregions, it is unclear to what extent their delineations of MTL cortex subregions overlap. Here, we provide an overview of cytoarchitectonic definitions of the entorhinal and parahippocampal cortices as well as Brodmann areas (BA) 35 and 36, as provided by four neuroanatomists from different laboratories, aiming to identify the rationale for overlapping and diverging delineations. Nissl-stained series were acquired from the temporal lobes of three human specimens (two right and one left hemisphere). Slices (50 μm thick) were prepared perpendicular to the long axis of the hippocampus spanning the entire longitudinal extent of the MTL cortex. Four neuroanatomists annotated MTL cortex subregions on digitized slices spaced 5 mm apart (pixel size 0.4 μm at 20× magnification). Parcellations, terminology, and border placement were compared among neuroanatomists. Cytoarchitectonic features of each subregion are described in detail. Qualitative analysis of the annotations showed higher agreement in the definitions of the entorhinal cortex and BA35, while the definitions of BA36 and the parahippocampal cortex exhibited less overlap among neuroanatomists. The degree of overlap of cytoarchitectonic definitions was partially reflected in the neuroanatomists' agreement on the respective delineations. Lower agreement in annotations was observed in transitional zones between structures where seminal cytoarchitectonic features are expressed less saliently. The results highlight that definitions and parcellations of the MTL cortex differ among neuroanatomical schools and thereby increase understanding of why these differences may arise. This work sets a crucial foundation to further advance anatomically-informed neuroimaging research on the human MTL cortex
Gene Expression and Functional Studies of the Optic Nerve Head Astrocyte Transcriptome from Normal African Americans and Caucasian Americans Donors
To determine whether optic nerve head (ONH) astrocytes, a key cellular component of glaucomatous neuropathy, exhibit differential gene expression in primary cultures of astrocytes from normal African American (AA) donors compared to astrocytes from normal Caucasian American (CA) donors.We used oligonucleotide Affymetrix microarray (HG U133A & HG U133A 2.0 chips) to compare gene expression levels in cultured ONH astrocytes from twelve CA and twelve AA normal age matched donor eyes. Chips were normalized with Robust Microarray Analysis (RMA) in R using Bioconductor. Significant differential gene expression levels were detected using mixed effects modeling and Statistical Analysis of Microarray (SAM). Functional analysis and Gene Ontology were used to classify differentially expressed genes. Differential gene expression was validated by quantitative real time RT-PCR. Protein levels were detected by Western blots and ELISA. Cell adhesion and migration assays tested physiological responses. Glutathione (GSH) assay detected levels of intracellular GSH.Multiple analyses selected 87 genes differentially expressed between normal AA and CA (P<0.01). The most relevant genes expressed in AA were categorized by function, including: signal transduction, response to stress, ECM genes, migration and cell adhesion.These data show that normal astrocytes from AA and CA normal donors display distinct expression profiles that impact astrocyte functions in the ONH. Our data suggests that differences in gene expression in ONH astrocytes may be specific to the development and/or progression of glaucoma in AA
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