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1.
Opt Lett ; 48(20): 5435-5438, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37831886

RESUMEN

We show that the Markovian dynamics of two coupled harmonic oscillators may be analyzed using a Schrödinger equation and an effective non-Hermitian Hamiltonian. This may be achieved by a non-unitary transformation that involves superoperators; such transformation enables the removal of quantum jump superoperators, which allows us to rewrite the Lindblad master equation in terms of a von Neumann-like equation with an effective non-Hermitian Hamiltonian. This may be generalized to an arbitrary number of interacting fields. Finally, by applying an extra non-unitary transformation, we may diagonalize the effective non-Hermitian Hamiltonian to obtain the evolution of any input state in a fully quantum domain.

2.
J Intellect Disabil Res ; 67(1): 35-48, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36253339

RESUMEN

BACKGROUND: The emotional state of parents of babies with Down syndrome affects their babies' development and their parent-child bonding. The aim for this study was to conduct a pilot randomised controlled evaluation of the effect of infant massage on parents of babies with Down syndrome. METHODS: This pilot study compared two groups (intervention and control), each with 16 parents of babies with Down syndrome. Indices of acceptance, engagement and awareness of influence were measured at two different time points (pre-test and after 5 weeks) using the 'This Is My Baby' Interview. The allocation of families to each group was randomised. The experimental group performed infant massage, applied by the parents, for 5 weeks, every day for at least 10 min. The massage protocol was based on the methodology created by Vimala McClure. Parents in the control group received the intervention after completion of the study. RESULTS: The indices of acceptance, commitment and awareness of influence improved in the experimental group and in the control group. The 2 × 2 mixed-model analysis of variance indicates a statistically significant group-by-time interaction for all indices (P < 0.001), which was significantly higher in the experimental group than in the control group. CONCLUSIONS: The application of infant massage, by parents to their babies, improves the rates of acceptance, commitment and awareness of influence of parents of babies with Down syndrome in the short term.


Asunto(s)
Síndrome de Down , Lactante , Humanos , Proyectos Piloto , Síndrome de Down/terapia , Padres/psicología , Masaje , Desarrollo Infantil
3.
Neurocase ; 28(1): 11-18, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35253627

RESUMEN

. COL18A1 gene mutations have been associated with Knobloch syndrome, which is characterized by ocular and brain abnormalities. Here we report a 4.5 years-old male child with autism and two novel COL18A1 mutations (NM_030582.4: c.1883_1891dup and c.1787C>T). Hypermetropic astigmatism, but not brain migration disorders, was observed. However, an asymmetric pattern of cerebellar perfusion and a smaller arcuate fascicle were found.  Low levels of collagen XVIII were also observed in the patient´s serum. Thus, biallelic loss-of-function mutations in COL18A1 may be a new cause of autism  without the brain malformations typically reported in patients with Knobloch syndrome.


Asunto(s)
Colágeno Tipo XVIII , Endostatinas , Cerebelo , Preescolar , Colágeno Tipo XVIII/genética , Encefalocele , Endostatinas/genética , Humanos , Masculino , Mutación , Neuroimagen , Degeneración Retiniana , Desprendimiento de Retina/congénito
4.
Opt Lett ; 46(18): 4690-4693, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34525083

RESUMEN

We show that the Kapitza-Dirac effect may be modeled by classical light propagation in photonic lattices having a square power law for the refraction index coefficient. The dynamics is shown to be fully soluble because both systems share the same time-independent Schrödinger equation: the angular Mathieu equation. We examine the trajectories of classical light propagating in such structures.

5.
J Appl Microbiol ; 131(1): 221-235, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33305511

RESUMEN

AIMS: Toxaphene is a persistent organic pollutant, composed of approximately 1000 highly chlorinated bicyclic terpenes. The purpose of this study was to evaluate if camphor, a structural analogue of toxaphene, could stimulate aerobic biotransformation of weathered toxaphene. METHODS AND RESULTS: Two enrichment cultures that degrade camphor as the sole carbon source were established from contaminated soil and biosolids. These cultures were used to evaluate aerobic transformation of weathered toxaphene. Only the biosolids culture could transform compounds of technical toxaphene (CTTs) in the presence of camphor, while no transformation was observed in the presence of glucose or with toxaphene as a sole carbon source. The transformed toxaphene had lower concentration of CTTs with longer retention times, and higher concentration of compounds with lower retention times. Gas chromatography with electron capture negative ion mass spectrometry (GC/ECNI-MS) showed that aerobic biotransformation mainly occurred with Cl8 - and Cl9 -CTTs compounds. The patterns of Cl6 - and Cl7 -CTTs were also simplified albeit to a much lesser extent. Seven camphor-degrading bacteria were isolated from the enrichment culture but none of them could degrade toxaphene. CONCLUSION: Camphor degrading culture can aerobically transform CCTs via reductive pathway probably by co-metabolism using camphor as a co-substrate. SIGNIFICANCE AND IMPACT OF THE STUDY: Since camphor is naturally produced by different plants, this study suggests that stimulation of aerobic transformation of toxaphene may occur in nature. Moreover plants, which produce camphor or similar compounds, might be used in bioremediation of contaminated soils.


Asunto(s)
Bacterias/metabolismo , Alcanfor/metabolismo , Insecticidas/metabolismo , Toxafeno/metabolismo , Aerobiosis , Bacterias/clasificación , Biodegradación Ambiental , Biotransformación , Cloro/metabolismo , Ionización de Llama , ARN Ribosómico 16S/genética , Suelo/química , Microbiología del Suelo
6.
Exp Eye Res ; 198: 108149, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32693084

RESUMEN

The retina acts as an independent clock informing the central pacemaker, the suprachiasmatic nucleus, under environmental light conditions, with consequences of such inputs for the central and peripheral nervous system. Differences in the behavior of the left and right retinas depending on environmental light conditions may influence the information projected to the brain hemispheres. The retina possesses neuropeptides that act as neurotransmitters or neuromodulators. Alanyl-aminopeptidase (AlaAP, EC 3.4.11.2) activity regulates some of these neuropeptides and therefore reflects their function. We analyzed AlaAP activity in the left and right retinas of adult male rats at successive time points under standard (12/12 h light/dark cycle) and nonstandard (constant light) conditions. AlaAP activity was measured fluorometrically using alanyl-beta-naphthylamide as the substrate. Under standard conditions, there were no differences in the left or right retina between time points, with the left retina predominating, particularly in the light period. In contrast, under constant light, no left versus right differences were observed, but significant differences between time points appeared. In comparison with standard conditions, constant conditions led to significantly higher AlaAP activity. Considering all the left retina data in comparison with all the right retina data, no correlation was found between the left and right retinas under standard conditions, but a significant positive correlation was observed under constant light. These results demonstrate an asymmetrical response of retinal AlaAP activity to changes in environmental light conditions, which may affect the functions in which the substrates of AlaAP are involved and the information projected to the brain hemispheres.


Asunto(s)
Antígenos CD13/metabolismo , Ritmo Circadiano/fisiología , Retina/enzimología , Animales , Masculino , Modelos Animales , Estimulación Luminosa , Fotoperiodo , Ratas , Estándares de Referencia
7.
Ann Hematol ; 96(10): 1699-1705, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28770277

RESUMEN

Chromosome 1q gains and 13q deletions are common cytogenetic aberrations in multiple myeloma (MM) that confer a poor prognosis. There are several techniques for the targeted study of these alterations, but interphase fluorescence in situ hybridization (FISH) is the current gold standard. The aim of the present study was to validate quantitative PCR (qPCR) as an alternative to FISH studies in CD138+-enriched plasma cells (PCs) from MM patients at diagnosis. We analyzed 1q gains and 13q deletions by qPCR in 57 and 60 MM patients, respectively. qPCR applicability was 84 and 88% for 1q and 13q, respectively. The qPCR and FISH methods had a sensitivity and specificity of 88 and 71% for 1q gains, and 79 and 100% for 13q deletions. A second qPCR assay for each region was carried out to confirm the previous results. Paired qPCR (two assays) and FISH results were available from 53 MM patients: 26 for 1q amplification and 27 for 13q deletion. qPCR assays gave concordant results (qPCR-consistent) in 20 of the 26 (77%) 1q gains and 25 of the 27 (93%) 13q deletions. Considering only the consistent data, the overall concordance among qPCR and FISH was 85 and 100% for 1q gains and 13q deletions, respectively. Our results show a substantial agreement between qPCR and the gold standard FISH technique, indicating the potential of qPCR as an alternative approach, particularly when the starting material is too scarce or cells are too damaged to obtain accurate results from FISH studies.


Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 13/genética , Cromosomas Humanos Par 1/genética , Mieloma Múltiple/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Femenino , Humanos , Hibridación Fluorescente in Situ , Masculino , Mieloma Múltiple/patología
8.
Horm Metab Res ; 46(8): 561-7, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24627106

RESUMEN

The renin-angiotensin system (RAS), vasopressin, and nitric oxide (NO) interact to regulate blood pressure at central and peripheral level. To improve our understanding of their interaction and their relationship with the hypothalamus and the cardiovascular system, we analyzed angiotensin- and vasopressin-metabolizing activities in hypothalamus (HT), left ventricle (LV), and plasma, collected from Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) treated or not with L-NAME [N(G)-nitro-L-arginine methyl ester], which inhibits the formation of NO and over-activates the sympathetic nervous system. Previous observations in WKY suggested higher formation of Ang III and Ang IV in the HT and higher availability of Ang II in plasma after L-NAME treatment. Our current results show higher formation of Ang IV and higher metabolism of vasopressin after treatment with L-NAME in the LV of WKY rats. In SHR treated with L-NAME, there is higher availability of Ang III in the HT leading to higher release of vasopressin together with lower formation of Ang 2-10. In their LV, however, there is an increase of vasopressinase. Interestingly, while the enzymatic activities in the HT and LV of WKY rats and control SHR are poorly correlated, they are well but inversely correlated in the L-NAME treated SHR. On the other hand, no significant correlations between enzymatic activities in HT or LV and plasma were noticed. Our results suggest that eNOS inhibition in SHR induces or enhances an inverse reciprocal interaction between HT and LV involving the RAS and vasopressin, which may be mediated by the autonomic nervous system.


Asunto(s)
Cistinil Aminopeptidasa/sangre , Endopeptidasas/sangre , Hipotálamo/enzimología , Miocardio/enzimología , NG-Nitroarginina Metil Éster/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Hipotálamo/efectos de los fármacos , Masculino , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Sistema Renina-Angiotensina/efectos de los fármacos , Solubilidad
9.
Sci Total Environ ; 949: 175006, 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39069184

RESUMEN

In this 9-year manipulative field experiment, we examined the impacts of experimental warming (2 °C, W), rainfall reduction (30 % decrease in annual rainfall, RR), and their combination (W + RR) on soil microbial communities and native vegetation in a semi-arid shrubland in south-eastern Spain. Warming had strong negative effects on plant performance across five coexisting native shrub species, consistently reducing their aboveground biomass growth and long-term survival. The impacts of rainfall reduction on plant growth and survival were species-specific and more variable. Warming strongly altered the soil microbial community alpha-diversity and changed the co-occurrence network structure. The relative abundance of symbiotic arbuscular mycorrhizal fungi (AMF) increased under W and W + RR, which could help buffer the direct negative impacts of climate change on their host plants nutrition and enhance their resistance to heat and drought stress. Indicator microbial taxa analyses evidenced that the marked sequence abundance of many plant pathogenic fungi, such as Phaeoacremonium, Cyberlindnera, Acremonium, Occultifur, Neodevriesia and Stagonosporopsis, increased significantly in the W and W + RR treatments. Moreover, the relative abundance of fungal animal pathogens and mycoparasites in soil also increased significantly under climate warming. Our findings indicate that warmer and drier conditions sustained over several years can alter the soil microbial community structure, composition, and network topology. The projected warmer and drier climate favours pathogenic fungi, which could offset the benefits of increased AMF abundance under warming and further aggravate the severe detrimental impacts of increased abiotic stress on native vegetation performance and ecosystem services in drylands.


Asunto(s)
Cambio Climático , Hongos , Micorrizas , Lluvia , Microbiología del Suelo , Hongos/fisiología , España , Micorrizas/fisiología , Suelo/química , Microbiota , Biodiversidad , Calentamiento Global
10.
Horm Metab Res ; 45(5): 344-8, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23225243

RESUMEN

Sexual dysfunction is a frequent adverse effect during antihypertensive therapy. However, the mechanisms responsible for these effects are not well understood. The renin-angiotensin system has been identified in testis where it may play a role in testicular function and be involved in the detrimental effects of antihypertensive drugs. Therefore, our objective was to compare the influence of captopril and propranolol on plasma testosterone levels and on hydrolyzing angiotensin's enzymes (angiotensinases) in the testis of spontaneously hypertensive rats (SHRs) and in control animals. Twenty-four adult male SHRs were used in this study; eight were treated with captopril in drinking water, 8 with propranolol, and 8 were controls. At the end of the 4 weeks treatment period, systolic blood pressure (SBP) was recorded, blood samples were collected, and the right testis was dissected after perfusion of the rat with saline. The soluble (Sol) and membrane-bound (MB) fractions were obtained after solubilization and ultracentrifugation. Fluorometric measurement of Sol and MB angiotensinase activities were performed using arylamide derivatives as substrates. Testosterone was measured by enzyme immunoassay. SBP decreased after captopril but did not change with propranolol treatment. Whereas captopril did not affect angiotensinase activities, highly significant reductions in Sol and MB angiotensinase activities, particularly glutamyl- and aspartyl-aminopeptidases, were observed after treatment with propranolol. Plasma testosterone decreased in captopril treated rats but propranolol had a greater effect. The present results support a general functional depression of the RAS cascade in the testis of propranolol-treated SHR, which may influence the sexual function of these animals.


Asunto(s)
Antihipertensivos/farmacología , Captopril/farmacología , Endopeptidasas/metabolismo , Propranolol/farmacología , Testículo/enzimología , Aminopeptidasas/metabolismo , Animales , Presión Sanguínea/efectos de los fármacos , Masculino , Ratas , Ratas Endogámicas SHR , Solubilidad , Testículo/efectos de los fármacos , Testosterona/sangre
11.
Ann Oncol ; 23(4): 1005-9, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21778302

RESUMEN

BACKGROUND: Standard treatment of advanced squamous cell carcinoma of the head and neck (SCCHN) is concurrent chemoradiation. Erlotinib is an oral tyrosine kinase inhibitor of epidermal growth factor receptor, which has shown activity in SCCHN. Phase I study aims to determine the maximum tolerated dose and dose-limiting toxicity (DLT) of adding erlotinib to chemoradiation therapy in patients with surgically resected locally advanced SCCHN. PATIENTS AND METHODS: Inclusion criteria--SCCHN patients with T3 or T4 primary lesion (except T3N0 with negative resection margins); pathologic N2-N3 disease; poor prognostic findings; age 18-70 years; Eastern Cooperative Oncology Group performance status of zero to one; no evidence of metastasis; adequate organic function and written informed consent. Study design--dose-escalating phase I study with three cohorts of three to six patients each that received increasing doses of erlotinib (100-150 mg/day p.o.) and cisplatin (30-40 mg/m(2) i.v., day 1) for 7 weeks. Radiotherapy--standard regimen of 1.8 Gy daily (5 fractions/week) to a maximum total dose of 63 Gy in 7 weeks. RESULTS: Thirteen male (median age: 57 years) were enrolled. Overall, the regimen was well tolerated. Two of three patients treated at dose level III (erlotinib: 150 mg/day; cisplatin: 40 mg/m(2)) developed DLT consisting of grade 3 infection and grade 3 mucositis. Other toxic effects included diarrhea, asthenia, and rash. Recommended dose for additional studies: erlotinib 150 mg/day p.o.; cisplatin 30 mg/m(2)/week i.v. CONCLUSION: Erlotinib can be safely combined with chemoradiation without requiring dose reduction of chemo- or radiotherapy in this postsurgical population.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/terapia , Quimioradioterapia/efectos adversos , Neoplasias de Cabeza y Cuello/terapia , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Cisplatino/administración & dosificación , Relación Dosis-Respuesta a Droga , Clorhidrato de Erlotinib , Femenino , Humanos , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Quinazolinas/administración & dosificación
12.
Horm Metab Res ; 44(2): 152-4, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22203440

RESUMEN

Reducing angiotensin II (Ang II) production via angiotensin-converting enzyme (ACE) inhibitors is a key approach for the treatment of hypertension. However, these inhibitors may also affect other enzymes, such as angiotensinases and vasopressinase, responsible for the metabolism of other peptides also involved in blood pressure control, such as Ang 2-10, Ang III, Ang IV, and vasopressin. We analyzed the activity of these enzymes in the hypothalamus, plasma, and kidney of normotensive adult male rats after inhibition of ACE with captopril. Aspartyl- (AspAP), glutamyl- (GluAP), alanyl- (AlaAP) and cystinyl-aminopeptidase (CysAP) activities were measured fluorimetrically using arylamides as substrates. Systolic blood pressure (SBP), water intake, and urine flow were also measured. Captopril reduced SBP and increased urine flow. In the hypothalamus, GluAP and AspAP increased, without significant changes in either AlaAP or CysAP. In contrast with effects in plasma, GluAP was unaffected, AspAP decreased, while AlaAP and CysAP increased. In the kidney, enzymatic activities did not change in the cortex, but decreased in the medulla. These data suggest that after ACE inhibition, the metabolism of Ang I in hypothalamus may lead mainly to Ang 2-10 formation. In plasma, the results suggest an increased formation of Ang IV together with increased vasopressinase activity. In the kidney, there is a reduction of vasopressinase activity in the medulla, suggesting a functional reduction of vasopressin in this location. The present data suggest the existence of alternative pathways in addition to ACE inhibition that might be involved in reducing BP after captopril treatment.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Captopril/farmacología , Cistinil Aminopeptidasa/metabolismo , Endopeptidasas/metabolismo , Hipertensión/tratamiento farmacológico , Hipertensión/enzimología , Hipotálamo/enzimología , Angiotensina II/antagonistas & inhibidores , Angiotensina II/sangre , Angiotensina II/metabolismo , Animales , Cistinil Aminopeptidasa/sangre , Ingestión de Líquidos/fisiología , Endopeptidasas/sangre , Hipertensión/orina , Hipotálamo/efectos de los fármacos , Riñón/efectos de los fármacos , Riñón/enzimología , Masculino , Ratas , Ratas Wistar
13.
Clin Transl Oncol ; 24(5): 796-808, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35013882

RESUMEN

Transarterial radioembolization (TARE) with yttrium-90 (Y90) is a promising alternative strategy to treat liver tumors and liver metastasis from colorectal cancer (CRC), as it selectively delivers radioactive isotopes to the tumor via the hepatic artery, sparring surrounding liver tissue. The landscape of TARE indications is constantly evolving. This strategy is considered for patients with hepatocellular carcinoma (HCC) with liver-confined disease and preserved liver function in whom neither TACE nor systemic therapy is possible. In patients with liver metastases from CRC, TARE is advised when other chemotherapeutic options have failed. Recent phase III trials have not succeeded to prove benefit in overall survival; however, it has helped to better understand the patients that may benefit from TARE based on subgroup analysis. New strategies and treatment combinations are being investigated in ongoing clinical trials. The aim of this review is to summarize the clinical applications of TARE in patients with gastrointestinal malignancies.


Asunto(s)
Braquiterapia , Carcinoma Hepatocelular , Quimioembolización Terapéutica , Neoplasias Gastrointestinales , Neoplasias Hepáticas , Carcinoma Hepatocelular/radioterapia , Neoplasias Gastrointestinales/tratamiento farmacológico , Neoplasias Gastrointestinales/radioterapia , Humanos , Neoplasias Hepáticas/radioterapia , Radioisótopos de Itrio/uso terapéutico
14.
Acta Clin Belg ; 77(1): 118-121, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32543299

RESUMEN

BACKGROUND: Weiss-Kruszka syndrome (WSKA) is a rare disorder caused by mutations in the ZNF462 gene or deletion of 9p31.2 chromosome region, involving ZNF462. The prevalence of WSKA is unknown as only 24 affected individuals have been described. This syndrome should be suspected in individuals presenting mild global developmental delay and common craniofacial abnormalities. CASE PRESENTATION: We presented a case of an infant, 3 years and 4-month life who presented pondostatural and psychomotor retardation, generalized hypotonia with hypermobility, bilateral palpebral ptosis, epicanthal folds, and poorly expressive facies as the main clinical features. These characteristics lead to the realization of genetics studies that resulted in the identification of a novel mutation c.3306dup; p.(Gln1103Thrfs*10) in ZNF462. CONCLUSIONS: WSKA should be suspected in individuals presenting mild global developmental delay, ptosis, downslanting palpebral fissures, exaggerated Cupid's Bow, arched eyebrows, epicanthal folds and short upturned nose with a bulbous tip. Hypertrophy of the ventricular septum and severe OSA were described in our patient and should be considered in future reviews of the disease. This case is added to the reduced number of publications previously reported regarding WSKA and contributes to understanding the genetic characteristics, clinical features, and diagnosis of this syndrome.Abbreviations: WSKA: Weiss-Kruszka syndrome; CP: craniofacial perimeter; WES: whole-exome sequencing; RSV: respiratory syncytial virus; OSA: obstructive sleep apnoea; ACMG: American College of Medical Genetics and Genomics.


Asunto(s)
Anomalías Craneofaciales , Proteínas de Unión al ADN/genética , Facies , Humanos , Lactante , Hipotonía Muscular , Mutación , Proteínas del Tejido Nervioso/genética , Síndrome , Factores de Transcripción/genética
15.
J Intern Med ; 270(3): 224-8, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21314738

RESUMEN

OBJECTIVES: Deficiency in the catabolism of triglyceride-rich lipoproteins is the main cause of childhood-onset chylomicronaemia syndrome. Missense mutations in lipoprotein lipase (LPL) or in proteins influencing LPL activity or stability have been shown to be critical determinants of chylomicronaemia syndrome. The main objective of this study was to assess the primary deficiency in five cases of childhood-onset chylomicronaemia syndrome. SETTING: Lipid clinic at a university hospital, SUBJECTS: Subjects presenting with severe hypertriglyceridaemia and chylomicronaemia syndrome in which reduced LPL activity and mass were observed. INTERVENTIONS: Analysis of LPL and GPIHBP1 genes. RESULTS: Amongst the five patients, one novel homozygous missense mutation (p.C68Y) in exon 3 of GPIHBP1 was identified. The other four patients were homozygous for the common LPL mutation p.G188E. CONCLUSION: These findings provide further evidence that GPIHBP1 is involved in the catabolism of triglyceride-rich lipoproteins and plays a role in childhood-onset chylomicronaemia.


Asunto(s)
Proteínas Portadoras/genética , Quilomicrones/sangre , Hipertrigliceridemia/sangre , Lipoproteína Lipasa/sangre , Mutación Missense , Edad de Inicio , Niño , Quilomicrones/genética , Exones , Femenino , Homocigoto , Humanos , Lipoproteína Lipasa/genética , Lipoproteína Lipasa/metabolismo , Masculino , Receptores de Lipoproteína , Síndrome
16.
Nat Cell Biol ; 3(8): 761-6, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11483963

RESUMEN

Cohesins, which have been characterized in budding yeast and Xenopus, are multisubunit protein complexes involved in sister chromatid cohesion. Regulation of the interactions among different cohesin subunits and the assembly/disassembly of the cohesin complex to chromatin are key steps in chromosome segregation. We previously characterized the mammalian STAG3 protein as a component of the synaptonemal complex that is specifically expressed in germinal cells, although its function in meiosis remains unknown. Here we show that STAG3 has a role in sister chromatid arm cohesion during mammalian meiosis I. Immunofluorescence results in prophase I cells suggest that STAG3 is a component of the axial/lateral element of the synaptonemal complex. In metaphase I, STAG3 is located at the interchromatid domain and is absent from the chiasma region. In late anaphase I and the later stages of meiosis, STAG3 is not detected. STAG3 interacts with the structural maintenance chromosome proteins SMC1 and SMC3, which have been reported to be subunits of the mitotic cohesin complex. We propose that STAG3 is a sister chromatid arm cohesin that is specific to mammalian meiosis I.


Asunto(s)
Cromátides/genética , Segregación Cromosómica/fisiología , Mamíferos/genética , Meiosis/genética , Proteínas Nucleares/genética , Intercambio de Cromátides Hermanas/genética , Animales , Proteínas de Ciclo Celular , Centrómero/genética , Centrómero/metabolismo , Proteínas Cromosómicas no Histona , Proteínas de Unión al ADN , Técnica del Anticuerpo Fluorescente , Proteínas Fúngicas , Haplorrinos , Masculino , Mamíferos/metabolismo , Ratones , Proteínas Nucleares/metabolismo , Técnicas de Cultivo de Órganos , Espermatocitos/citología , Espermatocitos/metabolismo , Testículo/citología , Testículo/metabolismo , Cohesinas
17.
Horm Metab Res ; 43(2): 86-91, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21120792

RESUMEN

The kind of fat in the diet modifies the profile of fatty acids in brain and also affects aminopeptidase activities in tissues. Although modifications in brain fatty acids, neurotransmitters, or enzymes due to dietary fat composition have been reported, no direct relationship has yet been described between specific brain fatty acid changes and neuropeptide metabolism following the fat composition of the diet. We investigated the lipid profile and some neuropeptidase activities in the frontal cortex of adult male rats after a period in which diets were supplemented with fatty acids differing in their degrees of saturation such as fish oil (rich in polyunsaturated fatty acids, PUFAs), olive oil (rich in monounsaturated fatty acids, MUFAs), and coconut oil (rich in saturated fatty acids, SAFAs). It is observed that the diet composition affects fatty acid distribution in the brain. Although there is no change of global aminopeptidase/neuropeptidase, their activities in the brain correlate positively or negatively with the dietary fat composition. It is hypothesized that fatty acid in the diet modifies membrane fluidity, peptidases tertiary structure, and therefore, the availability and function of neuropeptides. The present results support the notion that cognitive functions may be modulated depending on the type of fat used in the diet.


Asunto(s)
Aminopeptidasas/metabolismo , Corteza Cerebral/metabolismo , Grasas de la Dieta/análisis , Ácidos Grasos/metabolismo , Ratas/metabolismo , Alimentación Animal/análisis , Animales , Corteza Cerebral/enzimología , Dieta , Masculino , Neuropéptidos/metabolismo , Ratas Wistar
18.
Nat Med ; 6(2): 171-6, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10655105

RESUMEN

Here we show that the cell-cycle regulator p21 is involved in immune system function. T lymphocytes from p21-/- mice exhibit significant proliferative advantage over wild-type cells following prolonged stimulation, but not after primary activation. Consistent with this, p21-deficient mice accumulate abnormal amounts of CD4+ memory cells, and develop loss of tolerance towards nuclear antigens. Similar to human lupus, female p21-deficient mice develop antibodies against dsDNA, lymphadenopathy, and glomerulonephritis, leading to decreased viability. These data demonstrate a specialized role for p21 in the control of T-cell proliferation, tolerance to nuclear antigens, and female-prone lupus. These findings could be the basis for new therapeutic approaches to lupus.


Asunto(s)
División Celular/fisiología , Ciclinas/fisiología , Ligamiento Genético , Lupus Vulgar/patología , Linfocitos T/citología , Animales , Anticuerpos Antinucleares/inmunología , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , ADN/inmunología , Femenino , Glomerulonefritis/inmunología , Memoria Inmunológica , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factores Sexuales , Linfocitos T/inmunología
19.
Sci Adv ; 7(14)2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33811076

RESUMEN

Polaritons with directional in-plane propagation and ultralow losses in van der Waals (vdW) crystals promise unprecedented manipulation of light at the nanoscale. However, these polaritons present a crucial limitation: their directional propagation is intrinsically determined by the crystal structure of the host material, imposing forbidden directions of propagation. Here, we demonstrate that directional polaritons (in-plane hyperbolic phonon polaritons) in a vdW crystal (α-phase molybdenum trioxide) can be directed along forbidden directions by inducing an optical topological transition, which emerges when the slab is placed on a substrate with a given negative permittivity (4H-silicon carbide). By visualizing the transition in real space, we observe exotic polaritonic states between mutually orthogonal hyperbolic regimes, which unveil the topological origin of the transition: a gap opening in the dispersion. This work provides insights into optical topological transitions in vdW crystals, which introduce a route to direct light at the nanoscale.

20.
Opt Express ; 18(12): 13301-8, 2010 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-20588459

RESUMEN

We study the optical emission of single semiconductor quantum dots weakly coupled to a photonic-crystal micro-cavity. The linearly polarized emission of a selected quantum dot changes continuously its polarization angle, from nearly perpendicular to the cavity mode polarization at large detuning, to parallel at zero detuning, and reversing sign for negative detuning. The linear polarization rotation is qualitatively interpreted in terms of the detuning dependent mixing of the quantum dot and cavity states. The present result is relevant to achieve continuous control of the linear polarization in single photon emitters.

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