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OBJECTIVES: Hearing recovery following idiopathic sudden sensorineural hearing loss (ISSNHL) is influenced by various prognostic factors, and the presence of acute vestibular syndrome (AVS) may adversely impact auditory outcomes. Evaluating vestibular function in SSNHL patients could offer insights into predicting hearing recovery. This systematic review aims to assess whether the presence of AVS exacerbates the audiological prognosis of ISSNHL. DESIGN: A comprehensive systematic review was conducted using databases such as PubMed, Cochrane Library, EMBASE, and Scopus, encompassing articles published in the last decade. Included were retrospective and prospective case-control and cohort studies, as well as randomized clinical trials. Meta-analysis was performed based on the findings from these studies. RESULTS: Among 386 articles identified, six addressed the systematic review's question, all being retrospective studies. These articles collectively involved 393 patients for the meta-analysis. Vestibular function assessment methods varied widely, posing challenges for direct comparisons. The likelihood of unfavorable hearing outcomes was 2.29 times higher in patients with associated AVS. Hearing recovery was 3.22 times more likely to be worse in patients with altered cervical vestibular evoked myogenic potentials-air-conducted sound. Abnormal caloric test results showed no significant association with worse hearing prognosis, although patients with unaltered caloric tests demonstrated a significantly greater improvement in pure-tone audiometry. CONCLUSIONS: Hearing recovery from ISSNHL appears to be diminished in patients with associated AVS and abnormal vestibular test results.
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RESUMEN Los trastornos del sueño en el adulto mayor son una afección frecuente. Sin embargo, es una parte de la medicina relativamente nueva, dado que ha sido en los últimos 40 años cuando se ha trabajado realmente en ella. El objetivo de esta revisión es profundizar y actualizar aspectos diagnósticos y terapéuticos sobre dichos trastornos, lo cual constituye siempre un reto para el médico que atiende este grupo poblacional.
ABSTRACT Sleeping disorders in the elderly are a frequent condition. However, it is a part of relatively new medicine, since it has only been in the last 40 years it has really studied. The objective of this review is to deepen and update diagnostic and therapeutic aspects of these disorders, which is always a challenge for the doctor who attends this age group.
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B chromosomes (Bs) are supernumerary components of the genome and do not confer any advantages on the organisms that harbor them. The maintenance of Bs in natural populations is possible by their transmission at higher than Mendelian frequencies. Although drive is the key for understanding B chromosomes, the mechanism is largely unknown. We provide direct insights into the cellular mechanism of B chromosome drive in the male gametophyte of rye (Secale cereale). We found that nondisjunction of Bs is accompanied by centromere activity and is likely caused by extended cohesion of the B sister chromatids. The B centromere originated from an A centromere, which accumulated B-specific repeats and rearrangements. Because of unequal spindle formation at the first pollen mitosis, nondisjoined B chromatids preferentially become located toward the generative pole. The failure to resolve pericentromeric cohesion is under the control of the B-specific nondisjunction control region. Hence, a combination of nondisjunction and unequal spindle formation at first pollen mitosis results in the accumulation of Bs in the generative nucleus and therefore ensures their transmission at a higher than expected rate to the next generation.
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Cromosomas de las Plantas/fisiología , Mitosis , No Disyunción Genética , Polen/genética , Secale/genética , Centrómero/metabolismo , Cromosomas de las Plantas/ultraestructura , Reordenamiento Génico , Histonas/metabolismo , Datos de Secuencia Molecular , Polen/citología , Polen/metabolismo , Secale/ultraestructuraRESUMEN
We used rye-specific repetitive DNA sequences in fluorescence in situ hybridization (FISH) to paint the rye genome and to identify rye DNA in a wheat background. A 592 bp fragment from the rye-specific dispersed repetitive family R173 (named UCM600) was cloned and used as a FISH probe. UCM600 is dispersed over the seven rye chromosomes, being absent from the pericentromeric and subtelomeric regions. A similar pattern of distribution was also observed on the rye B chromosomes, but with weaker signals. The FISH hybridization patterns using UCM600 as probe were comparable with those obtained with the genomic in situ hybridization (GISH) procedure. There were, however, sharper signals and less background with FISH. UCM600 was combined with the rye-specific sequences Bilby and pSc200 to obtain a more complete painting. With these probes, the rye chromosomes were labeled with distinctive patterns; thus, allowing the rye cultivar 'Imperial' to be karyotyped. It was also possible to distinguish rye chromosomes in triticale and alien rye chromatin in wheat-rye addition and translocation lines. The distribution of UCM600 was similar in cultivated rye and in the wild Secale species Secale vavilovii Grossh., Secale sylvestre Host, and Secale africanum Stapf. Thus, UCM600 can be used to detect Secale DNA introgressed from wild species in a wheat background.
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Genoma de Planta/genética , Secale/genética , Secuencia de Bases , Cromosomas de las Plantas/genética , Clonación Molecular , Genes de Plantas , Hibridación Fluorescente in Situ , Datos de Secuencia Molecular , Translocación GenéticaRESUMEN
Mitochondrial DNA (mtDNA) mutations increase with age. However, the number of cells with predominantly mutated mtDNA is small in old animals. Here a new hypothesis is proposed: mtDNA fragments may insert into nuclear DNA contributing to aging and related diseases by alterations in the nucleus. Real-time PCR quantification shows that sequences of cytochrome oxidase III and 16S rRNA from mtDNA are present in highly purified nuclei from liver and brain in young and old rats. The sequences of these insertions revealed that they contain single nucleotide polymorphisms identical to those present in mtDNA of the same animal. Interestingly, the amount of mitochondrial sequences in nuclear DNA increases with age in both tissues. In situ hybridization of mtDNA to nuclear DNA confirms the presence of mtDNA sequences inside nuclear DNA in rat hepatocytes. Bone marrow metaphase cells from both young and old rats show mtDNA at centromeric regions in 20 out of the 2n=40 chromosomes. Consequently, mitochondria can be a major trigger of aging but the final target could also be the nucleus.