University of Gothenburg

About: University of Gothenburg is a education organization based out in Gothenburg, Sweden. It is known for research contribution in the topics: Population & Health care. The organization has 23855 authors who have published 65241 publications receiving 2606327 citations. The organization is also known as: Göteborg University & Gothenburg University.

Resonance frequency analysis of implants subjected to immediate or early functional occlusal loading. Successful vs. failing implants.

Abstract: OBJECTIVES: The objective of this study was to analyze the development of implant stability by repeated resonance frequency analysis (RFA) measurements during 1 year in 23 patients treated according to an immediate/early-loading protocol. The objective was also to evaluate the possible differences between failing and successful implants. MATERIAL AND METHODS: Eighty-one Branemark System implants were placed in 23 patients for immediate/early-occlusal loading in all jaw regions. Thirty of the implants were placed in extraction sockets and 62 were subjected to GBR procedures. Apart from clinical and radiographic examinations, the patients were followed with RFA at placement, prosthesis connection and after 1-3, 6 and 12 months. Statistical analyses were carried out to study the possible differences between implants that failed during the study period and implants that remained successful. RESULTS: Nine implants failed (11.2%) during the 1 year of loading. RFA showed a distinct different pattern between the implants that remained stable and the implants that were lost. The implants that failed during the course of the study showed a significantly lower stability already after 1 month. CONCLUSION: Within the limitations of this study, it is concluded that failing implants show a continuous decrease of stability until failure. Low RFA levels after 1 and 2 months seem to indicate an increased risk for future failure. This information may be used to avoid implant failure in the future by unloading implants with decreasing degree of stability with time as diagnosed with the RFA technique.

Individual common variants exert weak effects on the risk for autism spectrum disorders.

Abstract: While it is apparent that rare variation can play an important role in the genetic architecture of autism spectrum disorders (ASDs), the contribution of common variation to the risk of developing ASD is less clear. To produce a more comprehensive picture, we report Stage 2 of the Autism Genome Project genome-wide association study, adding 1301 ASD families and bringing the total to 2705 families analysed (Stages 1 and 2). In addition to evaluating the association of individual single nucleotide polymorphisms (SNPs), we also sought evidence that common variants, en masse, might affect the risk. Despite genotyping over a million SNPs covering the genome, no single SNP shows significant association with ASD or selected phenotypes at a genome-wide level. The SNP that achieves the smallest P-value from secondary analyses is rs1718101. It falls in CNTNAP2, a gene previously implicated in susceptibility for ASD. This SNP also shows modest association with age of word/phrase acquisition in ASD subjects, of interest because features of language development are also associated with other variation in CNTNAP2. In contrast, allele scores derived from the transmission of common alleles to Stage 1 cases significantly predict case status in the independent Stage 2 sample. Despite being significant, the variance explained by these allele scores was small (Vm< 1%). Based on results from individual SNPs and their en masse effect on risk, as inferred from the allele score results, it is reasonable to conclude that common variants affect the risk for ASD but their individual effects are modest.

Economic freedom and growth: decomposing the effects

Abstract: Most studies of the relation between economic freedom andgrowth of GDP have found a positive relation One problem inthis area is the choice of economic freedom measure A singlemeasure does not reflect the complex economic environment anda highly aggregated index makes it difficult to draw policyconclusions In this paper we investigate what specific typesof economic freedom measures that are important for growthThe robustness of the results is carefully analysed since thepotential problem with multicollinearity is one of thenegative effects of decomposing an index The results showthat economic freedom does matter for growth This does notmean that increasing economic freedom, defined in generalterms, is good for economic growth since some of thecategories in the index are insignificant and some of thesignificant variables have negative effects

Association of cerebrospinal fluid neurofilament light concentration with Alzheimer disease progression

Abstract: Importance The extent to which large-caliber axonal degeneration contributes to Alzheimer disease (AD) progression is unknown. Cerebrospinal fluid (CSF) neurofilament light (NFL) concentration is a general marker of damage to large-caliber myelinated axons. Objective To test whether CSF NFL concentration is associated with cognitive decline and imaging evidence of neurodegeneration and white matter change in AD. Design, Setting, and Participants A commercially available immunoassay was used to analyze CSF NFL concentration in a cohort of patients with AD (n = 95) or mild cognitive impairment (MCI) (n = 192) and in cognitively normal individuals (n = 110) from the Alzheimer’s Disease Neuroimaging Initiative. The study dates were January 2005 to December 2007. The NFL analysis was performed in November 2014. Main Outcomes and Measures Correlation was investigated among baseline CSF NFL concentration and longitudinal cognitive impairment, white matter change, and regional brain atrophy within each diagnostic group. Results Cerebrospinal fluid NFL concentration (median [interquartile range]) was higher in the AD dementia group (1479 [1134-1842] pg/mL), stable MCI group (no progression to AD during follow-up; 1182 [923-1687] pg/mL), and progressive MCI group (MCI with progression to AD dementia during follow-up; 1336 [1061-1693] pg/mL) compared with control participants (1047 [809-1265] pg/mL) ( P P = .01). In the MCI group, a higher CSF NFL concentration was associated with faster brain atrophy over time as measured by changes in whole-brain volume (β = −4177, P = .003), ventricular volume (β = 1835, P P P P P Conclusions and Relevance Cerebrospinal fluid NFL concentration is increased by the early clinical stage of AD and is associated with cognitive deterioration and structural brain changes over time. This finding corroborates the contention that degeneration of large-caliber axons is an important feature of AD neurodegeneration.

Aspects of growth hormone and insulin-like growth factor-I related to neuroprotection, regeneration, and functional plasticity in the adult brain.

Abstract: Apart from regulating somatic growth and metabolic processes, accumulating evidence suggests that the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis is involved in the regulation of brain growth, development, and myelination. In addition, both GH and IGF-I affect cognition and biochemistry in the adult brain. Some of the effects of GH are attributable to circulating IGF-I, while others may be due to IGF-I produced locally within the brain. Some of the shared effects in common to GH and IGF-I may also be explained by cross-talk between the GH and IGF-I transduction pathways, as indicated by recent data from other cell systems. Otherwise, it also seems that GH may act directly without involving IGF-I (either circulating or locally). Plasticity in the central nervous system (CNS) may be viewed as changes in the functional interplay between the major cell types, neurons, astrocytes, and oligodendrocytes. GH and IGF-I affect all three of these cell types in several ways. Apart from the neuroprotective effects of GH and IGF-I posited in different experimental models of CNS injury, IGF-I has been found to increase progenitor cell proliferation and new neurons, oligodendrocytes, and blood vessels in the dentate gyrus of the hippocampus. It appears that the MAPK signaling pathway is required for IGF-I-stimulated proliferation in vitro, whereas the PI3K/Akt or MAPK/Erk signaling pathway appears to mediate antiapoptotic effects. The increase of IGF-I on endothelial cell phenotype may explain the increase in cerebral arteriole density observed after GH treatment. The functional role of GH and IGF-I in the adult brain will be reviewed with reference to neurotransmitters, glucose metabolism, cerebral blood flow, gap junctional communication, dendritic arborization, exercise, enriched environment, depression, learning, memory, and aging. Briefly, these findings suggest that IGF-I functions as a putative regenerative agent in the adult CNS. Hitherto less studied regarding in these aspects, GH may have similar effects, especially as it is the main regulator of IGF-I in vivo. Some of the positive cognitive features of GH treatment are likely attributable to the mechanisms reviewed here.