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PURPOSE: Myocardial dysfunction is common in sepsis but optimal treatment strategies are unclear. The inodilator, levosimendan was suggested as a possible therapy; however, the levosimendan to prevent acute organ dysfunction in Sepsis (LeoPARDS) trial found it to have no benefit in reducing organ dysfunction in septic shock. In this study we evaluated the effects of levosimendan in patients with and without biochemical cardiac dysfunction and examined its non-inotropic effects. METHODS: Two cardiac biomarkers, troponin I (cTnI) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and five inflammatory mediators were measured in plasma from patients recruited to the LeoPARDS trial at baseline and over the first 6 days. Mean total Sequential Organ Failure Assessment (SOFA) score and 28-day mortality were compared between patients with normal and raised cTnI and NT-proBNP values, and between patients above and below median values. RESULTS: Levosimendan produced no benefit in SOFA score or 28-day mortality in patients with cardiac dysfunction. There was a statistically significant treatment by subgroup interaction (p = 0.04) in patients with NT-proBNP above or below the median value. Those with NT-proBNP values above the median receiving levosimendan had higher SOFA scores than those receiving placebo (mean daily total SOFA score 7.64 (4.41) vs 6.09 (3.88), mean difference 1.55, 95% CI 0.43-2.68). Levosimendan had no effect on the rate of decline of inflammatory biomarkers. CONCLUSION: Adding levosimendan to standard care in septic shock was not associated with less severe organ dysfunction nor lower mortality in patients with biochemical evidence of cardiac dysfunction.
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Cardiopatías/sangre , Cardiopatías/tratamiento farmacológico , Choque Séptico/complicaciones , Simendán/farmacología , Anciano , Biomarcadores/análisis , Biomarcadores/sangre , Quimiocina CCL2/análisis , Quimiocina CCL2/sangre , Método Doble Ciego , Femenino , Proteínas HSP90 de Choque Térmico/análisis , Proteínas HSP90 de Choque Térmico/sangre , Cardiopatías/fisiopatología , Humanos , Unidades de Cuidados Intensivos/organización & administración , Unidades de Cuidados Intensivos/estadística & datos numéricos , Interleucina-10/análisis , Interleucina-10/sangre , Interleucina-6/análisis , Interleucina-6/sangre , Interleucina-8/análisis , Interleucina-8/sangre , Masculino , Persona de Mediana Edad , Péptido Natriurético Encefálico/análisis , Péptido Natriurético Encefálico/sangre , Puntuaciones en la Disfunción de Órganos , Fragmentos de Péptidos/análisis , Fragmentos de Péptidos/sangre , Pronóstico , Choque Séptico/tratamiento farmacológico , Simendán/uso terapéutico , Troponina I/análisis , Troponina I/sangre , Reino UnidoRESUMEN
The inactive X chromosome (Xi) serves as a model for establishment and maintenance of repressed chromatin and the function of polycomb repressive complexes (PRC1/2). Here we show that Xi transiently relocates from the nuclear periphery towards the interior during its replication, in a process dependent on CIZ1. Compromised relocation of Xi in CIZ1-null primary mouse embryonic fibroblasts is accompanied by loss of PRC-mediated H2AK119Ub1 and H3K27me3, increased solubility of PRC2 catalytic subunit EZH2, and genome-wide deregulation of polycomb-regulated genes. Xi position in S phase is also corrupted in cells adapted to long-term culture (WT or CIZ1-null), and also accompanied by specific changes in EZH2 and its targets. The data are consistent with the idea that chromatin relocation during S phase contributes to maintenance of epigenetic landscape in primary cells, and that elevated soluble EZH2 is part of an error-prone mechanism by which modifying enzyme meets template when chromatin relocation is compromised.
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Diferenciación Celular/genética , Epigénesis Genética , Fibroblastos/metabolismo , Proteínas Nucleares/genética , Animales , Células Cultivadas , Cromatina/genética , Cromatina/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Fibroblastos/citología , Perfilación de la Expresión Génica , Histonas/metabolismo , Metilación , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Proteínas Nucleares/metabolismo , Fase S/genética , Factores de TiempoRESUMEN
BACKGROUND: Levosimendan is a calcium-sensitizing drug with inotropic and other properties that may improve outcomes in patients with sepsis. METHODS: We conducted a double-blind, randomized clinical trial to investigate whether levosimendan reduces the severity of organ dysfunction in adults with sepsis. Patients were randomly assigned to receive a blinded infusion of levosimendan (at a dose of 0.05 to 0.2 µg per kilogram of body weight per minute) for 24 hours or placebo in addition to standard care. The primary outcome was the mean daily Sequential Organ Failure Assessment (SOFA) score in the intensive care unit up to day 28 (scores for each of five systems range from 0 to 4, with higher scores indicating more severe dysfunction; maximum score, 20). Secondary outcomes included 28-day mortality, time to weaning from mechanical ventilation, and adverse events. RESULTS: The trial recruited 516 patients; 259 were assigned to receive levosimendan and 257 to receive placebo. There was no significant difference in the mean (±SD) SOFA score between the levosimendan group and the placebo group (6.68±3.96 vs. 6.06±3.89; mean difference, 0.61; 95% confidence interval [CI], -0.07 to 1.29; P=0.053). Mortality at 28 days was 34.5% in the levosimendan group and 30.9% in the placebo group (absolute difference, 3.6 percentage points; 95% CI, -4.5 to 11.7; P=0.43). Among patients requiring ventilation at baseline, those in the levosimendan group were less likely than those in the placebo group to be successfully weaned from mechanical ventilation over the period of 28 days (hazard ratio, 0.77; 95% CI, 0.60 to 0.97; P=0.03). More patients in the levosimendan group than in the placebo group had supraventricular tachyarrhythmia (3.1% vs. 0.4%; absolute difference, 2.7 percentage points; 95% CI, 0.1 to 5.3; P=0.04). CONCLUSIONS: The addition of levosimendan to standard treatment in adults with sepsis was not associated with less severe organ dysfunction or lower mortality. Levosimendan was associated with a lower likelihood of successful weaning from mechanical ventilation and a higher risk of supraventricular tachyarrhythmia. (Funded by the NIHR Efficacy and Mechanism Evaluation Programme and others; LeoPARDS Current Controlled Trials number, ISRCTN12776039 .).
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Abundant phytoplankton and bacteria were identified by high-throughput 16S rRNA tag Illumina sequencing of samples from water and ice phases collected during winter at commercial fish ponds and a sand pit lake within the UNESCO Trebon Basin Biosphere Reserve, Czech Republic. Bacterial reads were dominated by Proteobacteria and Bacteroidetes. Despite dominance by members of just two phyla, UniFrac principal coordinates analysis of the bacterial community separated the water community of Klec fish pond, as well as the ice-associated community of Klec-Sand Pit from other samples. Both phytoplankton and cyanobacteria were represented with hundreds of sequence reads per sample, a finding corroborated by microscopy. In particular, ice from Klec-Sand Pit contained high contributions from photoautotrophs accounting for 25% of total reads with reads dominated by single operational taxonomic units (OTUs) of the cyanobacterium Planktothrix sp. and two filamentous diatoms. Dominant OTUs recovered from ice were largely absent (< 0.01%) from underlying water suggestive of low floristic similarity of phytoplankton partitioned between these phases. Photosynthetic characterization of phototrophs resident in water and ice analysed by variable chlorophyll a fluorescence showed that communities from both phases were photosynthetically active, thus supporting ice as viable habitat for phytoplankton in freshwater lakes and reservoirs.
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Bacterias/clasificación , Agua Dulce/microbiología , Hielo , Fitoplancton/clasificación , Microbiología del Agua , Bacterias/genética , Bacterias/metabolismo , Biodiversidad , República Checa , Ecosistema , Fotosíntesis , Fitoplancton/genética , Fitoplancton/metabolismo , Estanques , Estaciones del AñoRESUMEN
BACKGROUND: Organ dysfunction consequent to infection ('severe sepsis') is the leading cause of admission to an intensive care unit (ICU). In both animal models and early clinical studies the calcium channel sensitizer levosimendan has been demonstrated to have potentially beneficial effects on organ function. The aims of the Levosimendan for the Prevention of Acute oRgan Dysfunction in Sepsis (LeoPARDS) trial are to identify whether a 24-hour infusion of levosimendan will improve organ dysfunction in adults who have septic shock and to establish the safety profile of levosimendan in this group of patients. METHODS/DESIGN: This is a multicenter, randomized, double-blind, parallel group, placebo-controlled trial. Adults fulfilling the criteria for systemic inflammatory response syndrome due to infection, and requiring vasopressor therapy, will be eligible for inclusion in the trial. Within 24 hours of meeting these inclusion criteria, patients will be randomized in a 1:1 ratio stratified by the ICU to receive either levosimendan (0.05 to 0.2 µg.kg⻹.min⻹ or placebo for 24 hours in addition to standard care. The primary outcome measure is the mean Sequential Organ Failure Assessment (SOFA) score while in the ICU. Secondary outcomes include: central venous oxygen saturations and cardiac output; incidence and severity of renal failure using the Acute Kidney Injury Network criteria; duration of renal replacement therapy; serum bilirubin; time to liberation from mechanical ventilation; 28-day, hospital, 3 and 6 month survival; ICU and hospital length-of-stay; and days free from catecholamine therapy. Blood and urine samples will be collected on the day of inclusion, at 24 hours, and on days 4 and 6 post-inclusion for investigation of the mechanisms by which levosimendan might improve organ function. Eighty patients will have additional blood samples taken to measure levels of levosimendan and its active metabolites OR-1896 and OR-1855. A total of 516 patients will be recruited from approximately 25 ICUs in the United Kingdom. DISCUSSION: This trial will test the efficacy of levosimendan to reduce acute organ dysfunction in adult patients who have septic shock and evaluate its biological mechanisms of action. TRIAL REGISTRATION: Current controlled trials ISRCTN12776039 (19 September 2013).
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Gasto Cardíaco/efectos de los fármacos , Cuidados Críticos/métodos , Hidrazonas/administración & dosificación , Insuficiencia Multiorgánica/tratamiento farmacológico , Piridazinas/administración & dosificación , Choque Séptico/tratamiento farmacológico , Adulto , Cardiotónicos/administración & dosificación , Cardiotónicos/sangre , Cardiotónicos/farmacocinética , Diafragma/efectos de los fármacos , Método Doble Ciego , Estudios de Seguimiento , Humanos , Hidrazonas/sangre , Hidrazonas/farmacocinética , Riñón/efectos de los fármacos , Insuficiencia Multiorgánica/etiología , Piridazinas/sangre , Piridazinas/farmacocinética , Flujo Sanguíneo Regional/efectos de los fármacos , Proyectos de Investigación , Choque Séptico/complicaciones , SimendánRESUMEN
The greater Himalayan region demarcates two of the most prominent linguistic phyla in Asia: Tibeto-Burman and Indo-European. Previous genetic surveys, mainly using Y-chromosome polymorphisms and/or mitochondrial DNA polymorphisms suggested a substantially reduced geneflow between populations belonging to these two phyla. These studies, however, have mainly focussed on populations residing far to the north and/or south of this mountain range, and have not been able to study geneflow patterns within the greater Himalayan region itself. We now report a detailed, linguistically informed, genetic survey of Tibeto-Burman and Indo-European speakers from the Himalayan countries Nepal and Bhutan based on autosomal microsatellite markers and compare these populations with surrounding regions. The genetic differentiation between populations within the Himalayas seems to be much higher than between populations in the neighbouring countries. We also observe a remarkable genetic differentiation between the Tibeto-Burman speaking populations on the one hand and Indo-European speaking populations on the other, suggesting that language and geography have played an equally large role in defining the genetic composition of present-day populations within the Himalayas.
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Cromosomas Humanos/genética , Genética de Población , Lingüística , Repeticiones de Microsatélite/genética , Asia , Flujo Génico , Técnicas de Genotipaje , HumanosRESUMEN
BACKGROUND: Electronic nose (E-nose) technology has been successfully used to diagnose a number of microbial infections. We have investigated the potential use of an E-nose for the diagnosis of ventilator-associated pneumonia (VAP) by detecting micro-organisms in bronchoalveolar lavage (BAL) fluid in a prospective comparative study of E-nose analysis and microbiology. MATERIALS AND METHODS: BAL samples were collected using a blind technique from 44 patients following a minimum of 72 h mechanical ventilation. Control samples were collected from six patients mechanically ventilated on the intensive care unit (ICU) immediately following elective surgery. Quantitative microbiological culture and E-nose headspace analysis of the BAL samples were undertaken. Multivariate analysis was applied to correlate E-nose response with microbiological growth. RESULTS: E-nose fingerprints correctly classified 77% of the BAL samples, with and without microbiological growth from patients not on antibiotics. Inclusion of patients on antibiotics resulted in 68% correct classification. Seventy per cent of isolates, cultured in the laboratory from the clinical samples, were accurately discriminated into four clinically significant groups. CONCLUSIONS: E-nose technology can accurately discriminate between different microbial species in BAL samples from ventilated patients on ICU at risk of developing VAP with accuracy comparable with accepted microbiological techniques.
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Líquido del Lavado Bronquioalveolar/microbiología , Lavado Broncoalveolar/métodos , Neumonía Asociada al Ventilador/microbiología , Femenino , Humanos , Masculino , Neumonía Asociada al Ventilador/diagnóstico , Estudios Prospectivos , Sensibilidad y EspecificidadRESUMEN
Abstract In The Netherlands, a web application for speech training, E-learning-based speech therapy (EST), has been developed for patients with dysarthria, a speech disorder resulting from acquired neurological impairments such as stroke or Parkinson's disease. In this report, the EST infrastructure and its potentials for both therapists and patients are elucidated. EST provides patients with dysarthria the opportunity to engage in intensive speech training in their own environment, in addition to undergoing the traditional face-to-face therapy. Moreover, patients with chronic dysarthria can use EST to independently maintain the quality of their speech once the face-to-face sessions with their speech therapist have been completed. This telerehabilitation application allows therapists to remotely compose speech training programs tailored to suit each individual patient. Moreover, therapists can remotely monitor and evaluate changes in the patient's speech. In addition to its value as a device for composing, monitoring, and carrying out web-based speech training, the EST system compiles a database of dysarthric speech. This database is vital for further scientific research in this area.
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Instrucción por Computador , Educación a Distancia/métodos , Internet , Sistemas en Línea , Trastornos del Habla/rehabilitación , Logopedia/métodos , Telemedicina/métodos , Bases de Datos Factuales , Humanos , Telemedicina/organización & administraciónRESUMEN
Twenty-six Y-chromosomal short tandem repeat (STR) loci were amplified in a sample of 769 unrelated males from Nepal, using two multiplex polymerase chain reaction (PCR) assays. The 26 loci gave a discriminating power of 0.997, with 59% unique haplotypes, and the highest frequency haplotype occurring 12 times. We identified novel alleles at four loci, microvariants at a further two, and nine examples of amelogenin-Y deletions (1.2%). Comparison with a similarly sized Bhutanese sample typed with the same markers suggested histories of isolation and drift, with drift having a greater effect in Bhutan. Extended (11-locus) haplotypes for the Nepalese samples have been submitted to the Y-STR Haplotype Reference Database (YHRD).
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Cromosomas Humanos Y , Frecuencia de los Genes , Genética de Población , Haplotipos , Secuencias Repetidas en Tándem , Amelogenina/genética , Deleción Cromosómica , Dermatoglifia del ADN , Genotipo , Humanos , Masculino , Nepal , Reacción en Cadena de la PolimerasaRESUMEN
The receptor tyrosine c-Kit and its cognate ligand, c-Kit ligand (KL, stem cell factor, SCF), are involved in ovarian follicular development in several animal species. We studied the expression of KL and c-Kit using in situ hybridization and immunohistochemistry in donated human ovarian cortical tissue. The KL transcripts were expressed in granulosa cells of primary follicles, whereas the expression of c-Kit was confined to the oocyte and granulosa cells in primary and secondary follicles. We employed an ovarian organ culture using firstly serum-containing and then serum-free medium to study the effects of KL and an anti-c-Kit antibody, ACK2, on the development and survival of ovarian follicles in vitro. Culture of ovarian cortical slices for 7 days resulted in a 37% increase in the number of primary follicles and a 6% increase in secondary follicles. The proportion of viable follicles decreased in all cultures. The addition of KL (1, 10 and 100 ng/ml) into the culture media did not affect the developmental stages of the follicles or the proportion of atretic follicles. Inclusion of ACK2 (800 ng/ml) in the culture medium significantly increased the proportion of atretic follicles on days 7 (49 vs 28% in control cultures) and 14 (62 vs 38%) of culture. In conclusion, c-Kit and KL are expressed in human ovaries during follicular development. Blocking the c-Kit receptor induces follicular atresia. The KL/c-Kit signaling system is likely to control the survival of human ovarian follicles during early follicular development.
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Folículo Ovárico/metabolismo , Proteínas Proto-Oncogénicas c-kit/análisis , Factor de Células Madre/análisis , Anticuerpos Monoclonales/farmacología , Northern Blotting/métodos , Femenino , Atresia Folicular , Humanos , Inmunohistoquímica/métodos , Hibridación in Situ/métodos , Técnicas de Cultivo de Órganos , Proteínas Proto-Oncogénicas c-kit/inmunología , Proteínas Proto-Oncogénicas c-kit/metabolismo , Factor de Células Madre/metabolismoRESUMEN
The use of cryopreserved human embryos in gene expression studies provides an additional source to the scarce embryos available for research. To validate their use we have implemented a quantitative RT-PCR to characterize the levels of the tuberous sclerosis, TSC2 gene in fresh and frozen-thawed human embryos. Frozen embryos were thawed using two different clinical protocols. In fresh embryos 9.95 fg of TSC2 cDNA was present in the unfertilized oocyte, which was comparable to the level on day 2 of preimplantation development. On day 3 there was a significant drop (P<0.001) to 6.8 fg, followed by an increase in cDNA levels to 10.8 fg (P<0.01) on day 6 at the expanded blastocyst stage. Day 2 frozen embryos possessed 50% less (P<0.001) TSC2 mRNA in comparison to the fresh embryos using thawing protocol one (from frozen to 37 degrees C) and 25% less TSC2 mRNA (P<0.01) with thawing protocol 2 (from frozen to room temperature). After culturing day 2 frozen embryos for an additional day they showed mRNA levels comparable with fresh day 3 embryos. There was no significant difference in the levels of TSC2 mRNA between fresh and frozen day 3 human embryos with either thawing protocol. This study demonstrates that cryopreservation does affect the normal pattern of gene expression during human preimplantation development, and that intact frozen-thawed embryos are not equivalent to their non-frozen counterparts. Furthermore human embryos frozen on day 2 appear to be more susceptible to temperature change than embryos frozen on day 3.
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Criopreservación , Desarrollo Embrionario/genética , Estabilidad del ARN , Proteínas Represoras/genética , Esclerosis Tuberosa/genética , Senescencia Celular , Embrión de Mamíferos/embriología , Embrión de Mamíferos/metabolismo , Femenino , Fertilización , Regulación del Desarrollo de la Expresión Génica , Humanos , Oocitos/citología , Oocitos/crecimiento & desarrollo , Oocitos/metabolismo , Embarazo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Tiempo , Proteína 2 del Complejo de la Esclerosis Tuberosa , Proteínas Supresoras de TumorRESUMEN
The degree of fragmentation during early cleavage is universally used as an indicator of embryo quality during human in vitro fertilization treatment. Extensive fragmentation has been associated with reduced blastocyst formation and implantation. We examined the relationship between early fragmentation and subsequent allocation of cells to the trophectoderm and inner cell mass in the human blastocyst. We retrospectively analyzed data from 363 monospermic human embryos that exhibited varying degrees of fragmentation on Day 2. Embryos were cultured from Day 2 to Day 6 in Earle balanced salt solution with 1 mM glucose and human serum albumin. Rates of development and blastocyst formation were measured. The number of cells in the trophectoderm and inner cell mass and the incidence of apoptosis were assessed following differential labeling with polynucleotide-specific fluorochromes. Increasing fragmentation resulted in reduced blastocyst formation and lower blastocyst cell numbers. For minimal and moderate levels of fragmentation, the reduction in cell numbers was confined largely to the trophectoderm and a steady number of inner cell mass cells was maintained. However, with extensive fragmentation of more than 25%, cell numbers in both lineages were reduced in the few embryos that formed blastocysts. Apoptotic nuclei were present in both the trophectoderm and inner cell mass, with the lowest incidence in blastocysts that had developed from embryos with minor (5-10%) fragmentation. Paradoxically, higher levels of apoptosis were seen in embryos of excellent morphology, suggesting a possible role in regulation of cell number.
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Blastocisto/citología , Citoplasma/ultraestructura , Embrión de Mamíferos/citología , Fertilización In Vitro , Apoptosis , Blastocisto/fisiología , Recuento de Células , Fase de Segmentación del Huevo , Desarrollo Embrionario y Fetal , Femenino , Humanos , Estudios RetrospectivosRESUMEN
By conventional assessments, in vitro fertilization (IVF) is one of the safest medical treatments. But producing new life brings immense responsibilities. Recently, there have been disquieting reports of foetal abnormality after these treatments and here we evaluate the potential risks associated with intracytoplasmic sperm injection (ICSI), embryo freezing and pre-implantation genetic diagnosis. In our opinion, before translating new techniques into practice, more research, particularly in animals,is desirable. In addition, better child follow-up and a fresh approach to regulation are also needed.
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Fertilización In Vitro , Inyecciones de Esperma Intracitoplasmáticas , Aberraciones Cromosómicas , Anomalías Congénitas/etiología , Femenino , Humanos , Masculino , Modelos Biológicos , Embarazo , Resultado del Embarazo , RiesgoRESUMEN
OBJECTIVE: To assess the effect of a single intraoperative application of 750 cGy of beta irradiation on the outcome of trabeculectomy for uncontrolled open-angle glaucoma. DESIGN: A prospective, randomized, double-blind, placebo-controlled clinical trial. PARTICIPANTS: Sixty-one eyes of 61 Caucasian patients at low risk of filtering surgery failure, with poorly controlled primary or secondary open-angle glaucoma undergoing routine trabeculectomy. METHOD: Patients were randomly assigned to control or beta irradiation groups. All patients underwent standard trabeculectomy with fornix-based conjunctival incision. Eyes assigned to beta irradiation received 750 cGy of beta irradiation directly over the sclerostomy site on completion of conjunctival suturing. An identical but inactive applicator was applied to control eyes, delivering no radiation. Both operator and patient remained masked to the assignment for the 12-month follow-up period. MAIN OUTCOME MEASURES: The main outcome measure was intraocular pressure (IOP) control. Complete success of IOP control was defined as an IOP less than 21 mmHg at 12 months without need for additional medication. Qualified success was defined as an IOP less than 21 mmHg at 12 months where additional medication was required. RESULTS: Complete success of IOP control was achieved in 19 (86%) control eyes and 35 (90%) irradiated eyes (P = 1.0). Qualified success of IOP control was achieved in 21 (95%) control eyes and 39 (100%) irradiated eyes at 12 months follow-up (P = 1.0) CONCLUSIONS: We experienced a very high success rate of filtration surgery in this select population without adjunctive irradiation. Our sample size was too small to show any improvement in success with use of beta irradiation in this group. Other studies would have to be done to determine whether it may have measurable benefit in cases with a high risk of filtration failure.
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Glaucoma de Ángulo Abierto/radioterapia , Glaucoma de Ángulo Abierto/cirugía , Trabeculectomía , Anciano , Método Doble Ciego , Femenino , Humanos , Presión Intraocular , Masculino , Estudios Prospectivos , Radioterapia Adyuvante , Resultado del TratamientoRESUMEN
The pathways of micro- and megagametophyte development in Agave fourcroydes (henequén) and A. angustifolia were studied. We used histology and light microscopy to observe anther ontogeny and ovary differentiation in relation to flower bud size. Both species have the same sexual reproductive strategies and gametophyte development that may be divided into three phases: (1) premeiotic, which includes the establishment of the megaspore mother cell and the pollen mother cell; (2) meiotic, the formation of mature microspores and functional megaspores; (3) postmeiotic, which encompasses the development of mature pollen grains and the formation of the embryo sac. A successive type microsporogenesis was found in both species with formation of T-shaped tetrads and binuclear pollen grains. In vitro germination tests revealed very low pollen fertility. The female gametophyte is formed from two micropylar megaspore cells after the first meiotic division (bisporic type). Male and female gametogenesis occur asynchronously with microsporogenesis finishing before macrosporogenesis. The results so far show that the formation of male and female gametophytes in henequén is affected at different stages and that these alterations might be responsible for the low fertility shown by this species.
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The Mexican marigold (Tagetes erecta) produces inflorescences of intense yellow color that contain high levels of xanthophylls, particularly lutein, which makes it a suitable model for the study of carotenoid biosynthesis and regulation throughout the development of the inflorescences. However, these studies require the recovery of total RNA from floral buds and inflorescences at different developmental stages, each of which presents specific extraction problems. Four protocols were tested, but only through the modification of one of them was it possible to obtain total RNA of sufficient quality and quantity to perform RT-PCR and Northern blots and to construct a cDNA library. This article presents the modified protocol for the recovery of total RNA from carotenoid-rich plant tissues.
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Asteraceae/genética , ARN de Planta/aislamiento & purificación , Asteraceae/química , Asteraceae/crecimiento & desarrollo , Carotenoides/análisis , Precipitación Química , Electroforesis en Gel de Agar , Tallos de la Planta/química , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Espectrofotometría UltravioletaRESUMEN
Plants of Tagetes erecta L. (marigold) cultivated in vitro in ventilated containers exhibited greater control of leaf water loss and increased survival in the field than plants cultivated in sealed containers. Increased field survival of plants cultivated in ventilated containers was attributed to higher levels of endogenous abscisic acid (ABA). Therefore, ABA was supplied exogenously to plants in sealed or ventilated containers by adding ABA (10(-6), 10(-5), 10(-4) M) to the in vitro culture media in order to evaluate control of leaf water loss, growth and field survival. The addition of 10(-4) M ABA to the culture media in sealed containers produced plants that had similar control of leaf water loss and were morphologically similar to plants cultivated in ventilated containers without the addition of ABA. Field survival of 10(-4) M ABA plants (75%) was increased compared to plants cultivated in sealed containers without ABA (31%), with survival being closer to that of plants cultivated in ventilated containers (90-100%). Plants cultivated with 10(-4) M ABA (sealed and ventilated) also exhibited increased plant vigour and leaf area in the field compared to plants cultivated without ABA. The results suggest that the limited field survival and growth of plants cultured in vitro are related to the limited ABA concentrations they accumulate while in vitro. Consequently, conditions that increase the endogenous ABA concentrations of in vitro plants (like ventilation or ABA addition to the medium) would improve the control of leaf water loss, field survival and plant vigour.
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Ácido Abscísico/fisiología , Magnoliopsida/fisiología , Hojas de la Planta/fisiología , Magnoliopsida/crecimiento & desarrollo , Magnoliopsida/metabolismo , Hojas de la Planta/metabolismo , Agua/metabolismoRESUMEN
Os resultados da literatura sugerem que o resultado do tratamento com FIV-TE para pacientes com endometriose depende do estadiamento da doença, sendo que pacientes com endometriose severa têm uma elevada taxa de insucesso. A presença de abortamento é supostamente mais prevalente em mulheres em tratmento para endometriose. Cento e quarenta pacientes com endometriose submeteram-se a 182 ciclos de FIV-TE utilizando a GnRH. Pacientes com endometriose como única patologia foram alocadas em um grupo, e os resultados foram comparados com outros três grupos de pacientes submetidas ao mesmo tratamento, durante o mesmo período. O gupo 1 era composto de casais com fator masculino (45 ciclos);grupo 2, casais com ESCA (196 ciclos), e grupo 3, casais com fator tubário como única causa (1.139 ciclos). A idade média das pacientes, o número médio de ampolas de HMG utilizads, os níveis séricos de E2 no dia do ECG, o número de dias de HMG, o número médio de oócitos aspirados e a taxa de aspiraçäo näo foram significativamente diferentes. A taxa de fertilizaçäo foi significativamente inferior no grupo 1, sendo que nenhuma diferença foi observada entre osdemais três grupos. O número médio de embriöes normalmente fertilizados näo foi significativamente diferente. O número de embriöes transferidos por ciclo e a taxa de implantaçäo foi semelhante nos quatro grupos. A taxa de gravidez por TE foide 39 por cento no grupo 1;48 por cento no grupo 2;45 por cento no grupo 3 e 40 por cento no Grupo 4. A taxa de abortamento foi de zero para o grupo 1; 3,9 por cento para o grupo 2; 3,9 por cento para o grupo 3 e, diferente do exposto em todos os artigos prévios, nenhuma das pacientes grávidas e com endometriose apresentou abortamento. O grupo de endometriose foi dividido de acordo com a classificaçäo do AFS-r e analisado separadamente. Nenhuma diferença foi encontrada nos resultados entre as pacientes com estádio I-II e III-IV. Nossos resultados sugerem que a utilizaçäo de GnRH para supressäo hipofisária melhora os resultados de FIV-TE em pacientes com endometriose. A presença de endometriose e seu grau de severidade näo alteraram significativamente os resultados de FIV-TE, além disso näo encontramos evidências de elevaçäo nas taxas de abortamento espontâneo