Search results for "Opus"
showing 10 items of 346 documents
Cellular composition and organization of the spinal cord central canal during metamorphosis of the frogXenopus laevis
2017
Studying the cellular composition and morphological changes of cells lining the central canal during Xenopus laevis metamorphosis could contribute to understand postnatal development and spinal cord regeneration. Here we report the analysis of central canal cells at different stages during metamorphosis using immunofluorescence for protein markers expression, transmission and scanning electron microscopy and cell proliferation assays. The central canal was regionalized according to expression of glial markers, ultrastructure, and proliferation in dorsal, lateral, and ventral domains with differences between larvae and froglets. In regenerative larvae, all cell types were uniciliated, have a…
Largest neurosurgical social media group and its impact on communication and research
2022
Item does not contain fulltext BACKGROUND: The use of social media to communicate and disseminate knowledge has increased exponentially, especially in the field of neurosurgery. 'Neurosurgery cocktail' (NC) was developed by a group of young neurosurgeons as a means of sharing didactic materials and clinical experiences via social media. It connects 35.000 neurosurgeons worldwide on multiple platforms, primarily Facebook and Twitter. Given the rising utilization of social media in neurosurgery, the popularity of NC has also increased since its inception. In this study, the authors surveyed the social media analytics of NC for both Facebook and Twitter. Besides, we reviewed the literature on …
Genes coding for intermediate filament proteins closely related to the hagfish "thread keratins (TK)" alpha and gamma also exist in lamprey, teleosts…
2005
The "thread keratins (TK)" alpha and gamma so far have been considered highly specialized intermediate filament (IF) proteins restricted to hagfish. From lamprey, we now have sequenced five novel IF proteins closely related to TKalpha and TKgamma, respectively. Moreover, we have detected corresponding sequences in EST and genomic databases of teleosts and amphibians. The structure of the TKalpha genes and the positions of their deduced amino acid sequences in a phylogenetic tree clearly support their classification as type II keratins. The genes encoding TKgamma show a structure typical for type III IF proteins, whereas their positions in phylogenetic trees favor a close relationship to the…
Deficient membrane integration of the novel p.N14D-GJB2mutant associated with non-syndromic hearing impairment
2006
Mutations in GJB2, the gene encoding for the Gap Junction protein Connexin 26 (Cx26), have been established as the major cause of hereditary, non-syndromic hearing impairment (HI). We report here the identification of a novel point mutation in GJB2, c.40A>G [p.N14D], detected in compound heterozygosity with the c.35delG mutation in two brothers with moderate non-syndromic sensorineural HI. The mother who carried one wildtype and a p.N14D allele displayed normal hearing. The mutation leads to substitution of the neutral amino acid asparagine (N) by the negatively charged aspartic acid (D) at amino acid number 14, a position that is conserved among Cx26 of different organisms and among many o…
Human cationic amino acid transporter hCAT-3 is preferentially expressed in peripheral tissues.
2001
At least five distinct carrier proteins form the family of mammalian cationic amino acid transporters (CATs). We have cloned a cDNA containing the complete coding region of human CAT-3. hCAT-3 is glycosylated and localized to the plasma membrane. Transport studies in Xenopus laevis oocytes revealed that hCAT-3 is selective for cationic L-amino acids and exhibits a maximal transport activity similar to other CAT proteins. The apparent substrate affinity and sensitivity to trans-stimulation of hCAT-3 resembles most closely hCAT-2B. This is in contrast to rat and murine CAT-3 proteins that have been reported to display a very low activity and to be inhibited by neutral and anionic L-amino acid…
Mechanisms of Ca2+ liberation at fertilization
2005
The mechanisms underlying the Ca2+ release at fertilization of several animal organisms are reported. Four main classical theories are described, i.e., that of Ca2+ release following simple sperm contact and a G protein stimulation; that of simple sperm contact followed by a tyrosine kinase receptor activation; that of the necessity of introduction by sperm into the egg of molecules for Ca2+ release; and that the molecule introduced into the marine eggs for Ca2+ release is the same Ca2+. Two other mechanisms for Ca2+ release are also illustrated: that of ryanodine receptor stimulation and that of NAADP formation.
Frailty syndrome and pre-operative risk evaluation: A systematic review
2015
Abstract Background Frailty is a geriatric syndrome characterized by the clinical presentation of identifiable physical alterations and decreased physiological reserve. The assessment of frailty syndrome has been recently related with post-surgical outcomes and overall mortality in older individuals. Design and data sources We performed searches in Pubmed, Embase, Scopus, SCIELO and IME (Spanish medical index) databases from their start dates to February 2014 for original papers about the identification of the relationship between frailty and pre-operative risk evaluation in people aged 65 and over. Review methods We followed criteria of systematic PRISMA guidelines. Two independent reviewe…
Evidence for increased nitric oxide production in the auditory brain stem of the aged dwarf hamster (Phodopus sungorus): an NADPH-diaphorase histoche…
2000
Age-related changes of the auditory system such as presbyacusis are believed to be due, at least in part, to alterations of central structures. The superior olivary complex (SOC), a group of interrelated brain stem nuclei, projects to a variety of neuronal structures including the cochlea and the inferior colliculus (IC). The soluble gas nitric oxide (NO), believed to function as a neuroactive substance within the SOC and cochlea, is thought to be involved in ageing processes. Since it is unknown whether NO-production is altered in the ageing auditory system, the present study was conducted to investigate whether the number of NO-producing cells in the SOC is changed with increasing age. Th…
Photoperiod effects on bombesin- and cholecystokinin-like immunoreactivity in the suprachiasmatic nuclei of the Djungarian hamster (Phodopus sungorus)
1991
The immunocytochemical distribution of the putative satiety peptides bombesin (BBS) and cholecystokinin (CCK) were studied in the hypothalamic suprachiasmatic nuclei (SCN) of male and female Djungarian hamsters (Phodopus sungorus) held under either long (light/dark, LD 16:8 h) or short (LD 8:16) photoperiod. The animals were killed by perfusion with a fixative at the middle of the light period and the tissue was processed by routine immunohistochemical methods. Perikarya exhibiting BBS- or CCK-like immunoreactivity (LI) were found in the SCN of animals of all groups. Sex-related differences were not observed. In contrast, long-term exposure to short days decreased the number of neurons exhi…
Anterograde tracing of retinohypothalamic afferents with Fluoro-Gold
1997
The anterograde neuronal tracing properties of Fluoro-Gold (FG) were characterized in this study by its ability to label the retinohypothalamic tract (RHT) upon pressure injection of the substance into the vitrous body of the eye in the Djungarian hamster, Phodopus sungorus. Tracing was compared to the anterograde neuronal transport of cholera toxin B subunit (CTB), Fast blue (FB), Phaseolous vulgaris leucoagglutinin (PHA-L) and biocytin. After survival times that ranged from 24 h to 4 weeks, a major projection was found to the bilateral hypothalamic suprachiasmatic nuclei (SCN). Labeling was also found in the anterior medial preoptic nucleus and, in relatively sparse amounts, in the latera…