23 research outputs found
IGF-1 as a possible marker of early cognitive impairment: A pilot study
No full textInsulin-like growth factor (IGF)-1 is an important neurotrophic hormone. Disregulation of this hormone has been reported to influence the genesis of cognitive impairment and dementia in the elderly patients. We evaluated IGF-1 serum values and cognitive status in elder subjects. Primary endpoint was finding a possible link between IGF-1 values and MMSE scores, adjusted for age and sex. Elder patients (range 55–71 ys) were followed for up to 4 years (median 3.2 years). Cognitive status was assessed by Mini Mental State Examination (MMSE). A total of 210 subjects were enrolled. Yearly evaluation included routine laboratory tests, a complete physical examination and cognitive state measurement. At baseline evaluation, patients were divided into three groups: Healthy (MMSE > 26), Borderline (MMSE 24–26), Cognitive impairment (MMSE < 24). We used multiple linear regression with a scatter plot to compare IGF-1 and MMSE, adjusted for diagnosis of hypertension. Then, we checked the ROC curve, analyzing the AUC of our marker. At the baseline evaluation, no differences were found in the three groups for therapy and other diseases. Borderline subjects differed from other two groups, with a significant elevation of IGF-1 values (P < 0.05). The AUC curve of the yearly evaluation showed significant values (0.86 ± 0,02). This trial showed IGF-1 elevation in borderline subjects. Further studies will be performed in order to demonstrate the efficacy and sensibility of this serum marker
New physics pathways from B processes
No full textWe re-consider recent measures of RK and RKjavax.xml.bind.JAXBElement@26c6f3c, now compatible with the Standard Model expectations, as well as the results for the process BR(Bs→μ+μ−) alongside earlier determinations of RDjavax.xml.bind.JAXBElement@5a764aa4 and BR(Bc→τν). We provide analytic constraints on the associated Wilson coefficients in both the b→s and the b→c sectors. These allow us to estimate the scale of potential New Physics for generic extensions of the Standard Model. We then use the results to constrain the leptoquark landscape
Structural cerebellar correlates of cognitive functions in spinocerebellar Ataxia type 2
No full textSpinocerebellar ataxia type 2 (SCA2) is an autosomal dominant neurodegenerative disease involving the cerebellum and characterized by a typical motor syndrome. In addition, the presence of cognitive impairment is now widely acknowledged as a feature of SCA2. Given the extensive connections between the cerebellum and associative cerebral areas, it is reasonable to hypothesize that cerebellar neurodegeneration associated with SCA2 may impact on the cerebellar modulation of the cerebral cortex, thus resulting in functional impairment.
The aim of the present study was to investigate and quantitatively map the pattern of cerebellar gray matter (GM) atrophy due to SCA2 neurodegeneration and to correlate that with patients’ cognitive performances.
Cerebellar GM maps were extracted and compared between SCA2 patients (n=9) and controls (n=33) by using voxel-based morphometry. Furthermore, the relationship between cerebellar GM atrophy and neuropsychological scores of the patients was assessed. Specific cerebellar GM regions were found to be affected in patients. Additionally, GM loss in cognitive posterior lobules (VI, Crus I, Crus II, VIIB, IX) correlated with visuospatial, verbal memory and executive tasks, while additional correlations with motor anterior (V) and posterior (VIIIA, VIIIB) lobules were found for the tasks engaging motor and planning components.
Our results provide evidence that the SCA2 neurodegenerative process affects the cerebellar cortex and that MRI indices of atrophy in different cerebellar subregions may account for the specificity of cognitive symptomatology observed in patients, as result of a cerebello-cerebral dysregulation
The cerebellar topography of attention sub-components in spinocerebellar ataxia type 2
No full textSpinocerebellar ataxia type 2 (SCA2) is an autosomal dominant neurodegenerative disease characterized by a progressive cerebellar syndrome and multiple-domain cognitive impairments. The cerebellum is known to contribute to distinct functional networks related to higher-level functions. The aims of the present study were to investigate the different sub-components of attention and to analyse possible correlations between attention deficits and specific cerebellar regions in SCA2 patients.
To this purpose, 11 SCA2 patients underwent an exhaustive attention battery that evaluated several attention sub-components. The SCA2 group performed below the normal range in tasks assessing selective attention, divided attention, and sustained attention, obtaining negative Z-scores. These results were confirmed by non-parametric Mann-Whitney U tests that showed significant differences between SCA2 and control subjects in the same sub-components of the attention battery, allowing us to speculate on cerebellar involvement when a high cognitive demand is required (i.e., multisensory integration, sequencing, prediction of events, and inhibition of inappropriate response behaviours).
The voxel-based morphometry analysis showed a pattern of significantly reduced grey matter volume in specific cerebellar lobules. In particular, the SCA2 patients showed significant grey matter loss in bilateral regions of the anterior cerebellar hemisphere (I-V) and in the posterior lobe (VI-IX) and posterior vermis (VI-IX).
Statistical analysis found significant correlations between grey matter reductions in the VIIb/VIIIa cerebellar lobules and impairments in Sustained and Divided Attention tasks and between grey matter reduction in the vermal VI lobule and impairment in the Go/NoGo task.
For the first time, the study demonstrated the involvement of specific cerebellar lobules in different sub-components of the attention domain, giving further support to the inclusion of the cerebellum within the attention network
Adaptive modification of the cat’s vestibulospinal reflex during sustained and combined roll tilt of the whole animal and forepaw rotation: cerebellar mechanisms.
No full textAbstract—In decerebrate cats, the electromyogram (EMG)
activity of the forelimb extensor triceps brachii (TB) increases
during side-down roll tilt of the whole animal (vestibulospinal
reflex, VSR) at about 0.15 Hz. (10°), while decreases
during side up tilt. On the other hand, the TB activity
increases during dorsal flexion of the ipsilateral forepaw
(0.15 Hz, 5°–10°), but decreases during ventral flexion. In six
experiments, these stimuli were synergistically associated
(side-down tilt coincided with dorsal flexion of the forepaw),
so that the EMG modulation of the TB activity was greater
than that induced by the individual stimuli. During a 3-h
period of this sustained stimulation, the amplitude of the pure
VSR progressively increased to reach the maximum value at
the end of the third hour and persisted unmodified during the
post-adaptation period (1 h). In three experiments, animal tilt
and forepaw rotation were antagonistically associated (sidedown tilt coincided with ventral flexion of the forepaw). In these instances the VSR gain remained on the average stable, but, at the end of the 3-h period of combined stimulation, a proportion of TB responses to animal tilt howed a phase reversal. In a digitigrade animal like the cat, a dorsal flexion of the wrist is associated with a decrease in limb length and would occur when the extensor tone is not appropriate to support body weight; we propose, therefore, that somatosensory volleys elicited by wrist rotation modify the gain of VSR so as to maintain postural stability. Inactivation, on the side of muscle recording, of the corticocerebellar region which projects to the lateral vestibular nucleus of Deiters, by local microinjection of the GABA-A agonist muscimol (0.5 l at 16 g/l), decreased the already adapted gain of VSR. In conclusion, the results of this study suggest that somatosensory reafferent inputs to the cerebellar vermis are used to plastically modify the gain of VSR, when external forces produce changes in the final posture of the foot during animal tilt
A mouse embryonic stem cell bank for inducible overexpression of human chromosome 21 genes
No full textA mouse embryonic stem cell bank for inducible overexpression of human chromosome 21 genes.
No full textAbstract
BACKGROUND:
Dosage imbalance is responsible for several genetic diseases, among which Down syndrome is caused by the trisomy of human chromosome 21.
RESULTS:
To elucidate the extent to which the dosage imbalance of specific human chromosome 21 genes perturb distinct molecular pathways, we developed the first mouse embryonic stem (ES) cell bank of human chromosome 21 genes. The human chromosome 21-mouse ES cell bank includes, in triplicate clones, 32 human chromosome 21 genes, which can be overexpressed in an inducible manner. Each clone was transcriptionally profiled in inducing versus non-inducing conditions. Analysis of the transcriptional response yielded results that were consistent with the perturbed gene's known function. Comparison between mouse ES cells containing the whole human chromosome 21 (trisomic mouse ES cells) and mouse ES cells overexpressing single human chromosome 21 genes allowed us to evaluate the contribution of single genes to the trisomic mouse ES cell transcriptome. In addition, for the clones overexpressing the Runx1 gene, we compared the transcriptome changes with the corresponding protein changes by mass spectroscopy analysis.
CONCLUSIONS:
We determined that only a subset of genes produces a strong transcriptional response when overexpressed in mouse ES cells and that this effect can be predicted taking into account the basal gene expression level and the protein secondary structure. We showed that the human chromosome 21-mouse ES cell bank is an important resource, which may be instrumental towards a better understanding of Down syndrome and other human aneuploidy disorders
A-cerca do pertencimento: percursos da Comunidade Invernada Paiol de Telha em um contexto de reivindicação de terra
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-graduação em Antropologia Social, Florianópolis, 2009O presente trabalho tem como foco de pesquisa as estratégias dos membros da comunidade Invernada Paiol de Telha em vistas de reaver as terras chamadas Fundão, ou Invernada Paiol de Telha, doadas a 13 escravos seus ascendentes, ainda no ano de 1860, pela então proprietária destes, Balbina Francisca de Siqueira, e das quais foram expulsos em meados da década de setenta. Uma vez fora das terras, os sucessores daqueles escravos vivem principalmente a partir de quatro diferentes bases espaciais ou núcleos, de acordo com os diversos atores envolvidos no processo de reivindicação: os municípios paranaenses de Guarapuava e Pinhão, um assentamento do INCRA, localizado na Colônia Socorro, distrito de Entre-Rios, e o acampamento por eles feito nas cercanias das terras reivindicadas. Dado o aspecto segmentar do grupo, as estratégias em vistas de reaver as terras ganham dimensões sempre novas, atreladas aos diferentes contextos nos quais se encontram seus membros. Estas estratégias revelam, criam e recriam modos diferentes de pensar o grupo, suas estratégias políticas, sua coletividade e sua história.This dissertation focuses on the strategies of Invernada Paiol de Telha community members in the quest of recovering the land called Fundão, or Invernada Paiol de Telha. This land was donated to 13 slaves - ancestors of many among the community -, back to the year 1860, by their owner Balbina Francisca de Siqueira. According to the various actors involved in the land claim process, once the successors of those slaves were expelled of the land in the mid-seventies, they organized themselves in four different territorial bases or cores: the municipal districts of Guarapuava and Pinhão in Paraná; a settlement of INCRA, located in Colônia Socorro, district of Entre-Rios/PR; and the camp made by them on the outskirts of the lands claimed. Due to the segmentary aspect of the group, the strategies used in trying to regain the land always assume distinct dimensions, related to the different contexts in which their members are involved. These strategies reveal, create and recreate different ways of thinking about the group, their political strategies, their collectivity, and their history
