RESUMEN
STUDY QUESTION: Can artificial intelligence (AI) algorithms developed to assist embryologists in evaluating embryo morphokinetics be enriched with multi-centric clinical data to better predict clinical pregnancy outcome? SUMMARY ANSWER: Training algorithms on multi-centric clinical data significantly increased AUC compared to algorithms that only analyzed the time-lapse system (TLS) videos. WHAT IS KNOWN ALREADY: Several AI-based algorithms have been developed to predict pregnancy, most of them based only on analysis of the time-lapse recording of embryo development. It remains unclear, however, whether considering numerous clinical features can improve the predictive performances of time-lapse based embryo evaluation. STUDY DESIGN, SIZE, DURATION: A dataset of 9986 embryos (95.60% known clinical pregnancy outcome, 32.47% frozen transfers) from 5226 patients from 14 European fertility centers (in two countries) recorded with three different TLS was used to train and validate the algorithms. A total of 31 clinical factors were collected. A separate test set (447 videos) was used to compare performances between embryologists and the algorithm. PARTICIPANTS/MATERIALS, SETTING, METHODS: Clinical pregnancy (defined as a pregnancy leading to a fetal heartbeat) outcome was first predicted using a 3D convolutional neural network that analyzed videos of the embryonic development up to 2 or 3 days of development (33% of the database) or up to 5 or 6 days of development (67% of the database). The output video score was then fed as input alongside clinical features to a gradient boosting algorithm that generated a second score corresponding to the hybrid model. AUC was computed across 7-fold of the validation dataset for both models. These predictions were compared to those of 13 senior embryologists made on the test dataset. MAIN RESULTS AND THE ROLE OF CHANCE: The average AUC of the hybrid model across all 7-fold was significantly higher than that of the video model (0.727 versus 0.684, respectively, P = 0.015; Wilcoxon test). A SHapley Additive exPlanations (SHAP) analysis of the hybrid model showed that the six first most important features to predict pregnancy were morphokinetics of the embryo (video score), oocyte age, total gonadotrophin dose intake, number of embryos generated, number of oocytes retrieved, and endometrium thickness. The hybrid model was shown to be superior to embryologists with respect to different metrics, including the balanced accuracy (P ≤ 0.003; Wilcoxon test). The likelihood of pregnancy was linearly linked to the hybrid score, with increasing odds ratio (maximum P-value = 0.001), demonstrating the ranking capacity of the model. Training individual hybrid models did not improve predictive performance. A clinic hold-out experiment was conducted and resulted in AUCs ranging between 0.63 and 0.73. Performance of the hybrid model did not vary between TLS or between subgroups of embryos transferred at different days of embryonic development. The hybrid model did fare better for patients older than 35 years (P < 0.001; Mann-Whitney test), and for fresh transfers (P < 0.001; Mann-Whitney test). LIMITATIONS, REASONS FOR CAUTION: Participant centers were located in two countries, thus limiting the generalization of our conclusion to wider subpopulations of patients. Not all clinical features were available for all embryos, thus limiting the performances of the hybrid model in some instances. WIDER IMPLICATIONS OF THE FINDINGS: Our study suggests that considering clinical data improves pregnancy predictive performances and that there is no need to retrain algorithms at the clinic level unless they follow strikingly different practices. This study characterizes a versatile AI algorithm with similar performance on different time-lapse microscopes and on embryos transferred at different development stages. It can also help with patients of different ages and protocols used but with varying performances, presumably because the task of predicting fetal heartbeat becomes more or less hard depending on the clinical context. This AI model can be made widely available and can help embryologists in a wide range of clinical scenarios to standardize their practices. STUDY FUNDING/COMPETING INTEREST(S): Funding for the study was provided by ImVitro with grant funding received in part from BPIFrance (Bourse French Tech Emergence (DOS0106572/00), Paris Innovation Amorçage (DOS0132841/00), and Aide au Développement DeepTech (DOS0152872/00)). A.B.-C. is a co-owner of, and holds stocks in, ImVitro SAS. A.B.-C. and F.D.M. hold a patent for 'Devices and processes for machine learning prediction of in vitro fertilization' (EP20305914.2). A.D., N.D., M.M.F., and F.D.M. are or have been employees of ImVitro and have been granted stock options. X.P.-V. has been paid as a consultant to ImVitro and has been granted stocks options of ImVitro. L.C.-D. and C.G.-S. have undertaken paid consultancy for ImVitro SAS. The remaining authors have no conflicts to declare. TRIAL REGISTRATION NUMBER: N/A.
Asunto(s)
Inteligencia Artificial , Transferencia de Embrión , Femenino , Embarazo , Humanos , Transferencia de Embrión/métodos , Frecuencia Cardíaca Fetal , Imagen de Lapso de Tiempo , Fertilización In Vitro , Índice de EmbarazoRESUMEN
We studied a large range of identical spherical oil/water microemulsion (O/W-MI) volume fractions. The O/W-MIs are stabilized by cetylpyridinium chloride ionic surfactant (CpCl) and octanol cosurfactant and dispersed in salt water. We grafted different numbers of dodecyl-(polyEthylene oxide)227-dodecyl triblock copolymer that we note (n(D-PEO227-D)), where n varies from 0 to 12. We accomplished the grafting process by replacing a small amount of CpCl and octanol with the appropriate n(D-PEO227-D). The aim is to determine the interaction/structure relationship of the covered microemulsions. Precisely, we are interested in a quantitative investigation of the influence of volume fraction Φ, temperature (T), and n(D-PEO227-D) on the microemulsion sol/gel transition. To this end, we first study the uncoated microemulsion structure depending only on Φ. Second, we determine the coated microemulsions structure as a function of n(D-PEO227-D) for different Φ. Third, we examine the effect of temperature on the uncoated and coated microemulsion. We show that the sol/gel transition is controlled by the three main parameters, Φ, T, and n(D-PEO227-D). Accordingly, the uncoated microemulsion sol/gel transition, at ambient temperature, occurred for Φ ≃ 33.65%. By increasing Φ, the O/W-MIs show a glass state, which occurs, along with the gel state, at Φ ≃ 37% and arises clearly at Φ ≃ 60%. The coated O/W-MI sol/gel transition is found to be linearly dependent on n(D-PEO227-D) and takes place for Φ ≃ 26.5% for n(D-PEO227-D) = 12. Ordinarily, the decrease in temperature leads to gel formation of microemulsions for low Φ. Additionally, in this work, we found that the gelation temperature increases linearly with n(D-PEO227-D). Thus, the parameter n(D-PEO227-D) can control the sol/gel transition of the O/W-MIs at ambient temperature and moderate Φ.
RESUMEN
Microemulsions are excellent systems for transdermal delivery of multifunctional drugs because they have the potential to improve drug absorption/permeation and handling limitations. Biocompatible polymers are used as a coating of microemulsions to avoid the interactions that can occur between the microemulsions and the skin. Thus, they protect and lubricate these transporter nanovesicles. In this paper, we studied decane/water microemulsions covered with hydrophobically modified PEO polymer (PEO-m). To reveal the effect of hydrophobically modified PEO (PEO-m) polymer on the shape, the micro-arrangement and the dynamics of the microemulsions, we used an integrated strategy combining Molecular Dynamics simulation (MD), Small-Angle Neutron Scattering experiments (SANS), and the Ornstein-Zernike integral equations with the Hypernetted Chain (HNC) closure relation. We determined the microemulsion shape in vitro using the renormalized intensities spectra from SANS experiments. We discussed the micro arrangements of microemulsions, in vitro and in silico, employing the pair correlation function g(r) and the structure factor S(q), obtained from the three approaches with good agreement. Thus, we used the validated MD simulations to calculate the microemulsion's dynamics properties that we discussed using the mean-squared displacement (MSD) and the diffusion coefficients. We found that the presence of moderate quantities of PEO-m, from 4 to 12 PEO-m per microemulsion, does not influence the microemulsion shape, increases the stability of the microemulsion, and slightly decrease the dynamics. Our in vitro and in silico results suggest that polymer incorporation, which has interesting in vivo implications, has no disadvantageous effects on the microemulsion properties.
RESUMEN
[This corrects the article DOI: 10.1039/D0RA09804C.].
RESUMEN
Less than 20% of African adolescents aged 10-19 years are aware of their HIV status, whereas HIV screening remains the gateway to care and while AIDS has become the leading cause of death among adolescents in Sub-Saharan Africa. According to the UNAIDS target, scalable HIV testing strategies specific to various age groups, populations, and geographical areas must be implemented to end the AIDS epidemic by 2030. Many African countries have implemented policies supporting HIV self-testing (HIVST). Evidence of practicability and efficiency of HIVST in Sub-Saharan Africa settings has been reported, including HIVST data among adolescents. Adapted strategies of HIVST are urgently needed to promote HIV testing among adolescents living in sub-Saharan Africa.
Asunto(s)
Infecciones por VIH , Autoevaluación , Adolescente , África del Sur del Sahara/epidemiología , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Prueba de VIH , HumanosRESUMEN
Molecular dynamics simulation (MD) is used to study the static and dynamic properties of positively charged decane/water microemulsions, for various volume fractions Φ (2.8%, 6.98%, 14%, and 26.5%). An effective hybrid potential combining three potentials, namely the hard-sphere repulsive potential, the van der Waals attractive potential, and the Yukawa repulsive potential, is used to describe the microemulsion interactions. The microemulsion shape is determined using the renormalized spectra in Porod representation. The appropriate potential parameters are tested using the Ornstein-Zernike integral equation approach with the Hypernetted Chain (HNC) closure relation by a comparison between the structure factor calculated from HNC and that obtained from Small Angle Neutron Scattering experiments (SANS). Thus, the micro arrangements of microemulsions have been analyzed using the pair correlation function g(r) and the structure factor S(q) obtained from HNC, SANS, and MD simulation using these parameters. The microemulsion dynamic properties were discussed using the mean-square displacement (MSD) and the diffusion coefficient D c calculated from MD simulations.
RESUMEN
HIV self-testing constitutes a new complementary strategy for HIV testing for general populations as well as "key" populations such as sex workers and their clients, men who have sex with men, and young people; it may help to reach the UNAIDS 90-90-90 objectives by 2020. In Africa, many pilot studies have been conducted, mainly in English-speaking countries, and they have demonstrated the high acceptability, practicability and clinical performance of HIV self-testing. Innovative strategies, including the translation of HIV self-test instructions for use into vernacular languages in association with educational pictograms, should be developed and evaluated in sub-Saharan Africa to implement HIV self-testing.
Asunto(s)
Serodiagnóstico del SIDA/métodos , Infecciones por VIH/diagnóstico , Autocuidado , África , Humanos , Guías de Práctica Clínica como AsuntoRESUMEN
Epilepsy is a neurological disorder for which the electroencephalogram (EEG) is the most important diagnostic tool. In particular, this diagnosis heavily depends on the detection of interictal (between seizures) paroxysmal epileptic discharges (IPED) in the EEG. This is a time-consuming task requiring significant training and experience. Automatic detection of these EEG patterns would greatly assist visual inspections of human readers. We present a new method, which allows automatic detection of IPED based on discrete wavelet decomposition and a random forest classifier. The algorithm was trained and cross validated using 17 subjects with scalp EEG and 10 subjects with intracranial EEG. The performance of this method reached 62% recall and 26% precision for surface EEG subjects and 63% recall and 53% precision for intracranial EEG subjects. Thus, the method hereby proposed has great potential for diagnosis support in clinical environments.
Asunto(s)
Electrocorticografía , Algoritmos , Epilepsia , Humanos , ConvulsionesRESUMEN
Methylene blue (MB) belongs to the phenothiazinium family. It has been used to treat a variety of human conditions and has beneficial effects on the central nervous system in rodents with and without brain alteration. The present study was designed to test whether chronic MB treatment taken after (therapeutic effect) or before (preventive effect) the onset of beta-amyloid pathology influences cognition in a transgenic mouse model (APP/PS1). In addition, the present study aims at revealing whether these behavioral effects might be related to brain alteration in beta-amyloid deposition. To this end, we conducted an in vivo study and compared two routes of drug administration, drinking water versus intraperitoneal injection. Results showed that transgenic mice treated with MB orally or following intraperitoneal injection were protected from cognitive impairments in a variety of social, learning, and exploratory tasks. Immunoreactive beta-amyloid deposition was significantly reduced in the hippocampus and adjacent cortex in MB-treated transgenic mice. Interestingly, these beneficial effects were observed independently of beta-amyloid load at the time of MB treatment. This suggests that MB treatment is beneficial at both therapeutic and preventive levels. Using solid-state High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS-NMR), we showed that MB administration after the onset of amyloid pathology significantly restored the concentration of two metabolites related to mitochondrial metabolism, namely alanine and lactate. We conclude that MB might be useful for the therapy and prevention of Alzheimer's disease. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/prevención & control , Azul de Metileno/farmacología , Azul de Metileno/uso terapéutico , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Administración Oral , Alanina/metabolismo , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Animales , Reacción de Prevención/efectos de los fármacos , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Discriminación en Psicología/efectos de los fármacos , Modelos Animales de Enfermedad , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Inyecciones Intraperitoneales , Ácido Láctico/metabolismo , Masculino , Azul de Metileno/administración & dosificación , Ratones , Ratones Transgénicos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Actividad Motora/efectos de los fármacos , Comportamiento de Nidificación/efectos de los fármacosRESUMEN
The myeloid differentiation primary response gene 88 (MyD88) product is the most common adaptor protein implicated in Toll-like and interleukin receptor (TIR) domain signaling and thus plays an important role in the innate immune system. Despite the fact that the MyD88-dependent pathway has emerged as an important player in cell death processes described in several animal models of neurodegenerative disorders, the contribution of this pathway to specific behavioral phenotypes has been largely ignored. To understand the full implication of this pathway, we tested MyD88(-/-) mice for both motor and cognitive functions in normal conditions. MyD88(-/-) mice displayed impaired spatial and working memory as detected by the Barnes maze, the water T-maze and the passive avoidance tests. Furthermore, MyD88(-/-) mice demonstrated hypolocomotion in the open-field and wheel activity systems, as well as impairments in motor coordination and balance using the pole test and the rotarod. Our findings shed light on behavioral alterations that are associated with the deletion of the MyD88 protein in physiological conditions. These behavioral effects should be taken into consideration when assessing the role of the MyD88-dependent pathway in various infectious and non-infectious conditions.
Asunto(s)
Trastornos del Conocimiento/genética , Trastornos del Conocimiento/psicología , Trastornos del Movimiento/genética , Trastornos del Movimiento/fisiopatología , Factor 88 de Diferenciación Mieloide/deficiencia , Animales , Reacción de Prevención/fisiología , Calor , Aprendizaje por Laberinto/fisiología , Memoria a Corto Plazo/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Actividad Motora/genética , Actividad Motora/fisiología , Dimensión del Dolor , Equilibrio Postural/genética , Equilibrio Postural/fisiología , Tiempo de Reacción/fisiologíaRESUMEN
BCL2-associated X protein (BAX) and B-cell leukaemia/lymphoma gene-2 (BCL2), which are, respectively, pro- and anti-apoptotic proteins of the BCL2 gene family, participate in the mitochondria-dependent apoptosis pathway. A correlation between low incidence of apoptosis in cumulus cells and oocyte maturation has previously been suggested in ovarian stimulation. However, little is known in unprimed ovaries. These authors have investigated whether BAX and BCL2 expression in cumulus cells affects the competency of in-vitro matured oocytes. We have studied 100 cumulus-oocyte-complexes (COC) recovered from unprimed ovaries of 13 women diagnosed with polycystic ovary syndrome (PCOS) and undergoing in-vitro maturation (IVM) with their informed consent. COC were matured for 24 h in a specific maturation medium and the cumulus was stripped from the oocyte. BAX and BCL2 mRNA content was measured in each COC using real-time polymerase chain reaction. We found that BCL2 mRNA expression was significantly higher in cumulus cells associated with mature oocytes than those associated with immature oocytes while BAX mRNA concentrations did not vary in cumulus cells. Regarding fertilization, higher BCL2 mRNA content was found in cumulus cells enclosing fertilized oocytes (0.140 versus 0.075; P = 0.03). These results suggest that BCL2 expression is strongly associated with the ability of oocytes to complete nuclear maturation and to be fertilized.
Asunto(s)
Células del Cúmulo/química , Genes bcl-2/genética , Oocitos/crecimiento & desarrollo , ARN Mensajero/análisis , Apoptosis/fisiología , Células Cultivadas , Células del Cúmulo/fisiología , Femenino , Fertilización In Vitro , Humanos , Síndrome del Ovario Poliquístico , Proteína X Asociada a bcl-2/genéticaRESUMEN
BACKGROUND: The RAS/RAF/MEK/ERK pathway is involved in the balance between melanocyte proliferation and differentiation. The same pathway is constitutively activated in cutaneous and uveal melanoma (UM) and related to tumour growth and survival. Whereas mutant BRAF and NRAS are responsible for the activation of the RAS/RAF/MEK/ERK pathway in most cutaneous melanoma, mutations in these genes are usually absent in UM. METHODS: We set out to explore the RAS/RAF/MEK/ERK pathway and used mitogen-activated protein kinase profiling and tyrosine kinase arrays. RESULTS: We identified Src as a kinase that is associated with ERK1/2 activation in UM. However, low Src levels and reduced ERK1/2 activation in metastatic cell lines suggest that proliferation in metastases can become independent of Src and RAS/RAF/MEK/ERK signalling. Inhibition of Src led to the growth reduction of primary UM cultures and cell lines, whereas metastatic cell line growth was only slightly reduced. CONCLUSION: We identified Src as an important kinase and a potential target for treatment in primary UM. Metastasis cell lines seemed largely resistant to Src inhibition and indicate that in metastases treatment, a different approach may be required.
Asunto(s)
Melanoma/enzimología , Neoplasias de la Úvea/enzimología , Familia-src Quinasas/metabolismo , Procesos de Crecimiento Celular/fisiología , Línea Celular Tumoral , Activación Enzimática , Humanos , Melanoma/patología , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Metástasis de la Neoplasia , Neoplasias de la Úvea/patologíaRESUMEN
Neuropsychiatric signs are critical in primary caregiving of Alzheimer patients and yet have been relatively ignored in murine models. In the present study, APPswe/PS1 bigenic mice had higher levels of irritability than non-transgenic controls as measured in the touch escape test. Moreover, APPswe/PS1 mice showed poorer nest building than controls and a higher duration of immobility in the forced swimming assay. These results are concordant with the hypothesis of increased apathy and depression-like behavior in an Alzheimer's disease model. In addition, APPswe/PS1 bigenic mice were deficient in retention of passive avoidance learning and left-right discrimination learning, concordant with previous findings in other Alzheimer-like models.
Asunto(s)
Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/psicología , Precursor de Proteína beta-Amiloide/genética , Conducta Animal/fisiología , Cognición/fisiología , Presenilina-1/genética , Animales , Reacción de Prevención/fisiología , Depresión/psicología , Aprendizaje Discriminativo/fisiología , Reacción de Fuga/fisiología , Femenino , Lateralidad Funcional/fisiología , Genio Irritable , Masculino , Aprendizaje por Laberinto/fisiología , Ratones , Ratones Transgénicos , Comportamiento de Nidificación , Natación/psicologíaRESUMEN
In-vitro maturation of oocytes (IVM) is a new IVF technology developed in order to avoid iatrogenic complications of standard IVF treatments. This technique is particularly useful in patients suffering from polycystic ovary syndrome (PCOS) who are concerned with the risk of ovarian hyperstimulation syndrome. This technique is nowadays routinely practised in many international centres. However, the efficiency of this technique needs to be improved for a better support of maturation conditions to maximize oocyte developmental competence. In order to improve IVM results, the efficiency of two IVM media was retrospectively compared. Ninety-three PCOS candidates undergoing their first IVM cycle were included in this study, and IVM was conducted with TCM-199 or IVM-Medicult medium. This is the first study comparing two maturation media. Both media resulted in the same results concerning total oocyte maturation, fertilization, early embryo development and pregnancy rates.
Asunto(s)
Medios de Cultivo/farmacología , Técnicas de Cultivo de Embriones , Oocitos/efectos de los fármacos , Oogénesis/efectos de los fármacos , Adulto , Células Cultivadas , Medios de Cultivo/química , Transferencia de Embrión , Femenino , Fertilización In Vitro , Humanos , Oocitos/fisiología , Embarazo , Índice de Embarazo , Estudios RetrospectivosAsunto(s)
Hemangioma/patología , Hemangioma/cirugía , Bazo/patología , Neoplasias del Bazo/patología , Neoplasias del Bazo/cirugía , Femenino , Hemangioma/complicaciones , Hemangioma/diagnóstico , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Esplenectomía , Neoplasias del Bazo/complicaciones , Neoplasias del Bazo/diagnóstico , Esplenomegalia/diagnóstico , Esplenomegalia/diagnóstico por imagen , Esplenomegalia/etiología , UltrasonografíaRESUMEN
The human spliceosomal Sm B/B' proteins are essential for the biogenesis of the snRNP particles. B/B' proteins contain several clusters of the PPPPGM/IR sequence, which occurs within the C-terminus of Sm B/B'. This sequence is very similar to the PPPPPGHR sequence of the cytoplasmic tail of the CD2 receptor and closely resembles the class II of SH3 ligands, suggesting a similarly important role. We report that a monoclonal antibody (3E10) against the PPPPPGHR sequence recognizes spliceosomal Sm B/B' proteins. Proteins that are specifically immunoprecipitated by 3E10 include Sm B, B', D1, D2, D3, E, F, and G. However, unlike Y12 and other anti-Sm immunoprecipitates, 3E10 immunoprecipitates appear to lack the U1 snRNP-specific proteins A and C and U snRNAs. These findings indicate that 3E10 recognizes a subset of Sm protein core and suggest the presence of snRNA-free Sm protein complex(es) in vivo. We propose that the epitope binding for 3E10 may become unaccessible upon interactions of Sm proteins and their subsequent incorporation into the core particles. The Sm proline-rich sequences may have an important role in mediating protein-protein interactions necessary for the proper snRNP core assembly or function, or both. To our knowledge, 3E10 is the first well characterized mAb specific for a subclass of polyproline-arg motif recognizing Sm B/B' and CD2 proteins. 3E10 antibody can be used to further characterize the nature of protein components in the snRNA-free Sm subcore protein complex(es) that are formed during the snRNP core assembly steps.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Autoantígenos/metabolismo , Dipéptidos/inmunología , Ribonucleoproteínas Nucleares Pequeñas/metabolismo , Secuencia de Aminoácidos , Especificidad de Anticuerpos , Arginina/inmunología , Autoantígenos/química , Autoantígenos/inmunología , Epítopos/inmunología , Humanos , Células Jurkat , Datos de Secuencia Molecular , Péptidos/inmunología , Pruebas de Precipitina , ARN Nuclear Pequeño/metabolismo , Ribonucleoproteínas Nucleares Pequeñas/química , Ribonucleoproteínas Nucleares Pequeñas/inmunología , Empalmosomas/metabolismo , Proteínas Nucleares snRNPRESUMEN
We have identified a 36 kD phosphoprotein that forms a complex with spliceosomal small nuclear ribonucleoproteins in lymphocyte extracts. This 36 kD protein is differentially phosphorylated in transformed human lymphoid cell lines and is regulated by IL-2 in peripheral blood T cells. We purified the 36 kD protein from human lymphocytes by employing a combination of immuno-affinity chromatography and preparative two-dimensional gel electrophoresis. Internal amino acid sequence analysis of the purified protein yielded two peptides that had perfect matches with sequences in the human protein serine/threonine phosphatase 6 (PP6). Using degenerate primers corresponding to the peptides, we obtained from a human T lymphocyte cDNA library a DNA fragment whose sequence is homologous to an EST cDNA clone (R05547). The predicted amino acid sequence of this clone showed over 98% sequence identity to human PP6. The identification of an IL-2 regulated type 6 protein serine/threonine phosphatase in lymphocytes was further substantiated by immunoblotting with anti-peptide antibodies. These findings suggest that PP6 is a component of a signaling pathway regulating cell cycle progression in response to IL-2 receptor stimulation.
Asunto(s)
Interleucina-2/farmacología , Fosfoproteínas Fosfatasas/metabolismo , Secuencia de Aminoácidos , Ciclo Celular , Clonación Molecular , ADN Complementario , Electroforesis en Gel Bidimensional , Activación Enzimática , Etiquetas de Secuencia Expresada , Humanos , Células Jurkat , Linfocitos/citología , Linfocitos/enzimología , Datos de Secuencia Molecular , Fosfoproteínas Fosfatasas/aislamiento & purificación , Fosforilación , Homología de Secuencia de AminoácidoRESUMEN
Cerebellar damage occurs during developmental stages in three mutant mice (staggerer, hot-foot, and lurcher), causing disturbances in posture and equilibrium. During three tests of motor coordination, the performances of staggerer mutants was inferior to that of normal mice and did not improve with extended practice for up to 7 days of training. The sensorimotor performance of hot-foot mutants and of lurcher mutants was also lower than that of normal mice. Nevertheless, hot-foot mutants showed evidence of learning in two of the three tests and lurcher mutants in all three tests. Cerebellar atrophy in the latter two mutants did not prevent sensorimotor learning, but instead impaired their ability to reach the same level of performance as that of normal mice.
Asunto(s)
Atrofia/fisiopatología , Cerebelo/fisiopatología , Aprendizaje , Ratones Mutantes , Animales , Conducta Animal , Femenino , Masculino , RatonesRESUMEN
Two types of cerebellar mutant mice (staggerer and lurcher) were evaluated during 5-day acquisition of a spatial learning task in a Z-maze filled with water. Although the number of errors and escape latencies decreased in normal mice, the acquisition of the cerebellar mutants was impaired but not abolished. These results indicate that the cerebellum has a role in spatial learning. Mice with cerebellar dysfunction take a more indirect route toward a goal during the course of swimming, when ataxic symptoms are no longer in evidence.