997 research outputs found
Ontogeny, phylogeny and functional morphology of the hominoid shoulder girdle
The shoulder is of particular relevance for resolving issues of locomotor ancestry since, as a group, living hominoids can be defined by the set of functional similarities that they share at this anatomical area (such as a scapula located on the back of the ribcage, and a shoulder joint adapted to allow extensive abduction). However, there is ongoing debate over which selective pressures are responsible for these shared morphologies. The current study addresses the question of whether the similarities in this anatomical structure in hominoids are a product of common ancestry (homology) or rather the product of parallelism (homoplasy) from an ontogenetic and phylogenetic perspectives. To this end, 30 measurements were collected on the clavicle, scapula and humerus of six hominoid species (Homo sapiens, Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus and Hylobates lar) and one macaque species (Macaca fascicularis); information on the dental development of each individual specimen was collected for the purpose of creating an ontogenetic sample for each species; all measurements were collected on surface scans of individual bones and analysed in a 3D environment (Geomagic Suite 12.1 and Amira 3.1), and all statistical analyses (ontogenetic, phylogenetic as well as within- and between-species differences) were conducted using R version 2.12.2 (R Core Team 2011). Overall my results provide a more detailed understanding of ontogenetic change in shoulder morphology across hominoid species, and demonstrate (1) a relative lack of phenotypic plasticity in other key traits (such as the proximal curvature of the clavicle and glenoid-axillary angle of the scapula), and (2) high levels of plasticity in key diagnostic traits of hominoid shoulder morphology in humeral torsion, the distal curvature of the clavicle, and the orientation of the scapular spine and glenoid fossa (all correlated with each other). However these seem to operate within phylogenetic constraints and to be modulated by the underlying anatomy of the thorax and shoulder girdle. Overall my results support the notion of an arboreal origin to the ape lineages and parallel evolution of quadrupedalism in the great apes
Biomimetic synthetic self-assembled hydrogels for cell transplantation
The development of three-dimensional matrices capable of recapitulating the main features of native extracellular matrix and contribute for the establishment of a favorable microenvironment for cell behavior and fate is expected to circumvent some of the main limitations of cell-based therapies. In this context, self-assembly has emerged as a promising strategy to engineer cell-compatible hydrogels. A wide number of synthetically-derived biopolymers, such as proteins, peptides and DNA/RNA, with intrinsic ability to self-assemble into well-defined nanofibrous structures, are being explored. The resulting hydrogels, in addition to closely resembling the architecture of native cellular microenvironments, present a versatile and dynamic behavior that allows them to be designed to undergo sol-to-gel transition in response to exogenous stimulus. This review presents an overview on the state-of-the-art of the different strategies being explored for the development of injectable synthetic self-assembled hydrogels for cell transplantation and/or recruitment of endogenous cells, with an emphasis on their biological performance, both in vitro and in vivo. Systems based on peptides are the most widely explored and have already generated promising results in pre-clinical in vivo studies involving different repair/regenerative scenarios, including cartilage, bone, nerve and heart. On the other hand, systems based on DNA and hybrid hydrogels are now emerging for application in the biomedical field with high potential. Finally, the main challenges hampering the translation of these systems to the clinic and the issues that need to be addressed for these to progress from bench-to-bedside are discussed.The authors would like to acknowledge the FEDER funds through the Programa Operacional Factores de Competitividade – COMPETE and the Portuguese funds through FCT – Fundação para a Ciência e a Tecnologia (HMSPICT/0020/2010, PTDC/SAU-BMA/118869/2010 and PEst/SAU/LA0002/2013) that supported this work. D Barros is supported by FCT (PD/BD/105953/2014) and I.F. Amaral by QREN through program ON.2, in the framework of "Project on Biomedical Engineering for Regenerative Therapies and Cancer” (NORTE-07-0124-FEDER-000005)
Synthetic matrix enhances transplanted satellite cell engraftment in dystrophic and aged skeletal muscle with comorbid trauma
Muscle satellite cells (MuSCs) play a central role in muscle regeneration, but their quantity and function decline with comorbidity of trauma, aging, and muscle diseases. Although transplantation of MuSCs in traumatically injured muscle in the comorbid context of aging or pathology is a strategy to boost muscle regeneration, an effective cell delivery strategy in these contexts has not been developed. We engineered a synthetic hydrogel-based matrix with optimal mechanical, cell-adhesive, and protease-degradable properties that promotes MuSC survival, proliferation, and differentiation. Furthermore, we establish a biomaterial-mediated cell delivery strategy for treating muscle trauma, where intramuscular injections may not be applicable. Delivery of MuSCs in the engineered matrix significantly improved in vivo cell survival, proliferation, and engraftment in nonirradiated and immunocompetent muscles of aged and dystrophic mice compared to collagen gels and cell-only controls. This platform may be suitable for treating craniofacial and limb muscle trauma, as well as postoperative wounds of elderly and dystrophic patients.Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the NIH under award numbers R21AR072287 (to Y.C.J.) and R01AR062368 (to A.J.G.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. This work was also funded by the Parker H. Petit Institute for Bioengineering and Bioscience Seed Grant Program (to A.J.G. and Y.C.J.)
Synthetic matrix enhances transplanted satellite cell engraftment in dystrophic and aged skeletal muscle with comorbid trauma
Muscle satellite cells (MuSCs) play a central role in muscle regeneration, but their quantity and function decline with comorbidity of trauma, aging, and muscle diseases. Although transplantation of MuSCs in traumatically injured muscle in the comorbid context of aging or pathology is a strategy to boost muscle regeneration, an effective cell delivery strategy in these contexts has not been developed. We engineered a synthetic hydrogel-based matrix with optimal mechanical, cell-adhesive, and protease-degradable properties that promotes MuSC survival, proliferation, and differentiation. Furthermore, we establish a biomaterial-mediated cell delivery strategy for treating muscle trauma, where intramuscular injections may not be applicable. Delivery of MuSCs in the engineered matrix significantly improved in vivo cell survival, proliferation, and engraftment in nonirradiated and immunocompetent muscles of aged and dystrophic mice compared to collagen gels and cell-only controls. This platform may be suitable for treating craniofacial and limb muscle trauma, as well as postoperative wounds of elderly and dystrophic patients.Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the NIH under award numbers R21AR072287 (to Y.C.J.) and R01AR062368 (to A.J.G.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. This work was also funded by the Parker H. Petit Institute for Bioengineering and Bioscience Seed Grant Program (to A.J.G. and Y.C.J.)
Prevalence of 35delG and Met34Thr GJB2 variants in Portuguese samples
Objective: To estimate the prevalence of 35delG and Met34Thr variants in a Portuguese children's community sample and to compare these frequencies with nonsyndromic hearing-loss patients.
Methods: 502 children were randomly selected among the 8647 participants of the Portuguese birth cohort Generation XXI, and screened for Met34Thr and 35delG variants in the GJB2 gene. These variants were also studied on 89 index-cases, observed in the Clinic of “Hereditary Hearing-loss” in Saint John's Hospital Center, presenting a mild to profound nonsyndromic hearing-loss.
Results: Among the 502 children from Generation XXI, 10 were heterozygous for the 35delG variant (95% Confidence Interval 1.03–3.68) and 1 homozygous (95% Confidence Interval 0.01–1.24). Other 10 children presented heterozygosity for the Met34Thr variant (95% Confidence Interval 1.03–3.68). No homozygous for the Met34Thr or compound heterozygotes (35delG/Met34Thr) were found. In the total of 89 nonsyndromic hearing-loss patients, 5 (95% Confidence Interval 2.11–12.8) were heterozygous and 7 (95% Confidence Interval 3.61–15.6) were homozygous for the 35delG variant. The Met34Thr variant was found in 4 patients, 2 heterozygous (95% Confidence Interval 0.13–8.31) and 2 homozygous (95% Confidence Interval 0.13–8.31).
Conclusion: The carrier frequency of 35delG and Met34Thr variants in a Portuguese sample was 1 in 50. Our data suggests that the 35delG mutation has an association with deafness. For the Met34Thr variant, no association was observed. However, Met34Thr seemed to conform to an additive model in hearing-loss
Characterization of the striatal extracellular matrix in a mouse model of Parkinson’s disease
Parkinson’s disease’s etiology is unknown, although evidence suggests the involvement of oxidative modifications of intracellular components in disease pathobiology. Despite the known involvement of the extracellular matrix in physiology and disease, the influence of oxidative stress on the matrix has been neglected. The chemical modifications that might accumulate in matrix components due to their long half-live and the low amount of extracellular antioxidants could also contribute to the disease and explain ineffective cellular therapies. The enriched striatal extracellular matrix from a mouse model of Parkinson’s disease was characterized by Raman spectroscopy. We found a matrix fingerprint of increased oxalate content and oxidative modifications. To uncover the effects of these changes on brain cells, we morphologically characterized the primary microglia used to repopulate this matrix and further quantified the effects on cellular mechanical stress by an intracellular fluorescence resonance energy transfer (FRET)-mechanosensor using the U-2 OS cell line. Our data suggest changes in microglia survival and morphology, and a decrease in cytoskeletal tension in response to the modified matrix from both hemispheres of 6-hydroxydopamine (6-OHDA)-lesioned animals. Collectively, these data suggest that the extracellular matrix is modified, and underscore the need for its thorough investigation, which may reveal new ways to improve therapies or may even reveal new therapies.This research was funded by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE 2020 Operational Program for Competitiveness and Internationalization (POCI), Portugal 2020, and Portuguese funds through FCT (ID/BIM/04293/2020), UnIC (UID/IC/00051/2019), iBiMED (UID/BIM/04501/2020 and POCI-01-0145-FEDER-007628), and LAQV/REQUIMTE (UIDB/50006/2020) research units as well as RV’s Fellowship Grant (IF/00286/2015). Ana Freitas acknowledges FCT for her PhD scholarship (SFRH/BD/111423/2015), Miguel Aroso is hired through the Scientific Employment Stimulus from FCT (CEECIND/03415/2017), and M.L. has an FCT RJEC Id 3762 contract.The authors thank Eduardo D Martín Montiel for his support, fruitful discussions, suggestions, and technical and scientific help. The authors also thank Sofia Lamas and all the i3S Animal facility personnel for their support with the animals throughout the study. Raman spectroscopy, together with wide field and confocal microscopy, were performed at the i3S Scientific Platform Bioimaging, member of the PPBI (Plataforma Portuguesa de Bioimagem, POCI-01-0145-FEDER-022122)
Evaluation of 99mTc-HYNIC-βAla-Bombesin(7-14) as an agent for pancreas tumor detection in mice
Multicenter study of the natural history and therapeutic responses of patients with chikungunya, focusing on acute and chronic musculoskeletal manifestations - a study protocol from the clinical and applied research in Chikungunya (REPLICK network)
BACKGROUND: Chikungunya is associated with high morbidity and the natural history of symptomatic infection has been divided into three phases (acute, post-acute, and chronic) according to the duration of musculoskeletal symptoms. Although this classification has been designed to help guide therapeutic decisions, it does not encompass the complexity of the clinical expression of the disease and does not assist in the evaluation of the prognosis of severity nor chronic disease. Thus, the current challenge is to identify and diagnose musculoskeletal disorders and to provide the optimal treatment in order to prevent perpetuation or progression to a potentially destructive disease course. METHODS: The study is the first product of the Clinical and Applied Research Network in Chikungunya (REPLICK). This is a prospective, outpatient department-based, multicenter cohort study in Brazil. Four work packages were defined: i. Clinical research; ii) Translational Science - comprising immunology and virology streams; iii) Epidemiology and Economics; iv) Therapeutic Response and clinical trials design. Scheduled appointments on days 21 (D21) ± 7 after enrollment, D90 ± 15, D120 ± 30, D180 ± 30; D360 ± 30; D720 ± 60, and D1080 ± 60 days. On these visits a panel of blood tests are collected in addition to the clinical report forms to obtain data on socio-demographic, medical history, physical examination and questionnaires devoted to the evaluation of musculoskeletal manifestations and overall health are performed. Participants are asked to consent for their specimens to be maintained in a biobank. Aliquots of blood, serum, saliva, PAXgene, and when clinically indicated to be examined, synovial fluid, are stored at -80° C. The study protocol was submitted and approved to the National IRB and local IRB at each study site. DISCUSSION: Standardized and harmonized patient cohorts are needed to provide better estimates of chronic arthralgia development, the clinical spectra of acute and chronic disease and investigation of associated risk factors. This study is the largest evaluation of the long-term sequelae of individuals infected with CHIKV in the Brazilian population focusing on musculoskeletal manifestations, mental health, quality of life, and chronic pain. This information will both define disease burden and costs associated with CHIKV infection, and better inform therapeutic guidelines
Breastfeeding patterns and exposure to suboptimal breastfeeding among children in developing countries: review and analysis of nationally representative surveys
BACKGROUND: Suboptimal breastfeeding is associated with higher mortality among infants and young children in the developing world. We describe patterns in 'exclusive breastfeeding' and 'any breastfeeding' rates and quantify exposure to suboptimal breastfeeding among children aged two years or younger in developing countries. METHODS: We reviewed nationally representative surveys that collected data on breastfeeding rates in 94 developing countries. Surveys were categorized by completeness and comprehensiveness of data. Complete and comprehensive data were analysed with minimum chi-square regression. With a fitting procedure, estimated parameters were used to impute missing observations for incomplete or non-comprehensive surveys. Breastfeeding indicators were calculated and are reported for 135 developing countries by UN region. RESULTS: Amongst infants aged six months or younger in the developing world, the prevalence of exclusive breastfeeding is 39% and the prevalence of no breastfeeding is 5.6%. The prevalence of continued breastfeeding is 86% and 68% for infants and children aged 6–11 and 12–23 months, respectively, in the developing world. Imputation expands population coverage of indicators, especially for infants. Breastfeeding trends are highly linear and estimated parameters defining the age-specific attrition hazard are robust. Survey-reported rates, particularly for exclusive breastfeeding, appear to have systematic upward bias, and exposure estimates must be considered conservative. CONCLUSIONS: Compliance with breastfeeding recommendations in developing countries is low, and more attention should be given to increasing breastfeeding – especially exclusive breastfeeding – and to monitoring trends. Although the introduction of more standardized and better validated survey instruments is desirable, since data coverage, completeness and comprehensiveness are extensive, global exposure assessment is relatively robust. Moreover, the regularity of breastfeeding patterns show existing survey data capture real biological and social phenomena. Our method for the analysis of breastfeeding rates provides a potent tool for summarizing trends, validating observations, translating and extrapolating indicators (as well as projecting and imputing estimates when necessary) and should support more effective child health monitoring
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